MEDICAL    .SCHOOL 
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SIFT  OF 

COLLEGE  OF  PHARMACY 


DEPART  Mil 


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WORKS  OF  PROF.  A.  F.  HOLLEMAN, 

Professor  Ordinarius  in  the  University  of 
Amsterdam,  Netherlands, 

PUBLISHED  BY 

JOHN  WILEY  &   SONS,   INC. 


A  Text-book  of  Inorganic  Chemistry. 

Issued  in  English  in  co-operation  with  HERMON 
CHARLES  COOPER.  Fifth  English  edition,  com- 
pletely revised,  viii  +521  pp.  6  by  9.  79  figures. 
Cloth,  $2.25  net. 

A  Text-Book  of  Organic  Chemistry. 

Edited  by  A.  JAMIESON  WALKER,  Ph.D.,  B.A., 
assisted  by  OWEN  E.  MOTT,  Ph.D.,  with  the  co- 
operation of  the  author.  Fourth  English  Edition, 
partly  rewritten.  xviii  +  621  pp.  6  by  9.  82 
figures.  Cloth,  $2.25  net. 

A  companion  volume  to  the  preceding,  and  forming 
with  it  a  comprehensive  treatise  on  pure  Chemistry. 

A    Laboratory    Manual   of  Organic   Chemistry  for 
Beginners. 

An  Appendix  to  the  author's  Text-book  of  Organic 
Chemistry.  Edited  by  A.  JAMIESON  WALKER,  Ph.D., 
B.A.  With  the  co-operation  of  the  author.  Third 
English  Edition,  revised,  xvii  +  83  pp.  5  by  7J. 
Cloth,  $1.00  net. 


A 
LABORATORY   MANUAL 


OF 


ORGANIC    CHEMISTRY 

FOR    BEGINNERS. 


A.  F.  IIOLLEMAN,  PH.D.,  F.R.A.    AMST. 

Professor  Ordinarius  in  the  University  of  Amsterdam. 


AN  APPENDIX  TO   THE  AUTHOR'S  TEXT-BOOK  OF 
ORGANIC   CHEMISTRY 


EDITED   BY 

A.  JAMIESON  WALKER,  PH.D.,  B.A. 

WITH   THE    CO-OPERATION   OF   THE   AUTHOR. 


THIRD  EDITION. 
TOTAL    ISSUE,    FIVE    THOUSAND. 


College  ef  Pharmacy 


NEW  YORK 

JOHN  WILEY  &  SONS,  INC. 

LONDON:  CHAPMAN  &  HALL,  LIMITED 

1917 


Copyright,  1904,  1913, 

BY 

A.  JAMIESON  WALKER. 


(First  Edition  Entered  at  Stationers1  Hall.) 


CHRONOLOGICAL  SUMMARY. 

ENGLISH  EDITIONS. 

First  Edition:  June,  1904. 
First  Edition,  revised:  March,  1908. 
Second  Edition:  August,  1913. 
Third  Edition:  May,   1917. 


The  original  Dutch  edition  has  also  been  translated  into 
German,  Italian,  and  Russian. 


PRESS    OF 

BRAUNWORTH    &    CO. 

BOOK    MANUFACTURERS 

BROOKLYN.    N.    Y. 


AUTHOR'S  PREFACE    TO   THE   THIRD 
EDITION. 


THE  whole  of  the  manual  has  been  carefully  revised  and 
some  new  experiments  have  been  incorporated.  Certain 
obsolete  reactions,  and  others  too  difficult  for  the  average 
student,  have  been  omitted.  I  am  again  indebted  to  Dr. 
JAMIESON  WALKER  for  the  care  bestowed  by  him  on  the 
revision. 

A.  F.  HOLLEMAN. 

AMSTERDAM,  April,  1917. 

iii 


AUTHOR'S  PREFACE  TO   THE  REVISED 
FIRST  EDITION. 


IT  is  admitted  universally  that  chemistry  cannot  be  learnt 
by  the  study  of  text-books  only,  and  that  laboratory  practice 
is  essential.  A  student  new  to  the  science  derives  most  benefit 
from  a  laboratory  course  of  inorganic  preparations,  simple 
quantitative  experiments,  and  qualitative  inorganic  analysis. 
He  is  brought  thus  into  contact  with  work  closely  connected 
with  the  text-books  and  lectures  on  this  division  of  chemistry, 
and  is  enabled  to  understand  the  subject  much  better  than  by 
any  other  method. 

Formerly,  a  student  beginning  the  study  of  organic  chemic- 
try  usually  had  to  content  himself  with  text-books  and  lec- 
tures, and  very  seldom  had  the  opportunity  of  handling  the 
compounds  about  which  he  had  to  read.  There  was,  therefore, 
an  evident  lack  in  the  methods  of  teaching  the  elements  of 
organic  chemistry  adopted  in  the  Universities. 

A  number  of  years  have  elapsed  since  a  course  of  practical 
work  in  organic  chemistry  was  introduced  into  the  Universities 
of  the  Netherlands,  chiefly  through  the  influence  of  Professor 
FRANCHIMONT  of  Leyden.  This  laboratory  work  is  a  com- 
plement to  the  lectures,  and  has  proved  very  satisfactory. 

At  the  suggestion  of  Dr.  A.  JAMIESON  WALKER,  the  labora- 
tory manual  written  by  me  in  Dutch  for  this  purpose  is  issued 
now  in  English.  At  his  request,  I  have  revised  the  whole 


VI    AUTHOR'S  PREFACE  TO  REVISED  FIRST  EDITION 

text,  and  added  some  new  experiments.  In  most  instances 
I  have  indicated  the  weights  or  volumes  suitable  for  the  reac- 
tions, an  experience  of  many  years  having  taught  me  that 
students  always  employ  much  larger  quantities  than  are 
necessary.  The  amounts  prescribed  are  approximate,  and, 
to  ensure  the  success  of  the  experiments,  need  not  be  weighed 
or  measured  with  great  accuracy. 

It  should  be  mentioned  that  this  manual  is  related  intimately 
to  my  text-book  of  organic  chemistry,  and  constitutes  an 
appendix  to  it.  To  obtain  the  maximum  advantage  from  these 
experiments,  I  advise  the  student  first  to  study  them  with 
the  aid  of  the  text-book,  and  afterwards  to  carry  them  out 
in  the  laboratory.  This  is  the  only  method  by  which  he  can 
attain  to  a  thorough  comprehension  of  his  laboratory  work. 

A.  F.  HOLLEMAN. 
AMSTERDAM,  January,  1908. 


EDITOR'S   PREFACE  TO   THE   THIRD 
EDITION. 


THE  first  English  edition  of  this  manual  was  published 
in  1904,  and  a  revision  was  issued  in  1908.  Owing  to  the 
very  extensive  alterations  in  the  text  and  in  the  arrangement 
of  the  matter  in  Professor  Holleman's  "  Text-book  of  Organic 
Chemistry  "  during  the  preparation  of  the  last  two  editions, 
much  revision  was  necessary  for  the  second  edition  of  this 
volume,  published  in  1913.  For  the  present  issue  a  certain 
amount  of  new  matter  has  been  added,  and  I  have  to  thank 
Professor  Holleman  for  the  time  and  labour  devoted  by  him 
to  the  work. 

It  should  be  noted  that  the  references  printed  in  Clarendon 
type  in  the  text  are  to  the  paragraphs  of  the  fourth  edition  of 
Professor  Holleman's  "  Text-book  of  Organic  Chemistry/' 
and  not  to  those  of  former  editions. 

A.  JAMIESON  WALKEB. 
REPTON,  DERBY,  May,  1917. 

vii 


EDITOK'S  PEEFACE   TO  THE  REVISED 
FIRST  EDITION 


DURING  the  time  the  English  edition  of  Professor  HOLLE- 
MAN'S  "  Text-book  of  Organic  Chemistry  "  has  been  published, 
it  has  taken  a  foremost  place  among  works  on  the  science  for 
students'  use.  This  volume  constitutes  an  appendix  to  the 
text-book,  and  forms  an  introductory  guide  to  laboratory  work 
in  organic  chemistry,  as  well  as  a  compendium  of  experiments 
suitable  for  lecture-table  illustration.  Its  mission  is  not  to 
displace  the  standard  works  on  organic  preparations,  but  to 
supplement  them  by  bridging  a  gap  between  theory  and  prac- 
tice which  they  do  not,  and  cannot,  span.  The  text  has  been 
brought  up  to  date  for  the  present  reprint. 

The  translation  is  from  a  completely  revised  and  consider- 
ably extended  copy  of  the  Dutch  edition,  specially  prepared 
by  Professor  HOLLEMAN  for  the  purpose.  To  facilitate 
reference,  I  have  added  paragraph  headings,  and  all  the 
manuscript  and  proof-sheets  have  been  corrected  by  the 
author,  to  whom  I  am  much  indebted  for  his  careful  revision. 

References  in  the  text  printed  in  Clarendon  type  are  to  my 
translation  of  Professor  HOLLEMAN'S  "  Leerboek  der  Organische 
Chemie,"  and  those  to  "  Inorganic  Chemistry  "  to  Dr.  COOPER'S 
translation  of  his  "  Leerboek  der  Anorganische  Chemie," 
published  by  Messrs.  JOHN  WILEY  and  SONS.,  Inc. 

My  thanks  are  due  to  the  publishers  for  the  care  they  have 
bestowed  on  the  production  of  the  work. 

A.  JAMIESON  WALKER. 
DERBY,  ENGLAND,  January,  1908. 

viii 


CONTENTS. 


Light  figures   refer  to  pages;     old-style    figures   to  the  author's    "Text-book    of 
Organic  Chemistry." 

PAGE 

I.  QUALITATIVE  ANALYSIS  OF  CARBON  COMPOUNDS  (3-5) 1 

Detection  of  Carbon  and  Hydrogen  (3) 1 

Carbonization,  1.  Oxidation  with  copper  oxide,  1. 
Detection  of  Nitrogen  (4) 2 

LASSAIGNE'S    method,    2.     WILL    and    VARRENTRAP'S 

method,  2.     KJELDAHL'S  method,  2. 
Detection  of  the  Halogens  (5) 3 

BEILSTEIN'S  test,  3.     Calcium-oxide  test,  3. 
Detection  of  Sulphur  (5) 3 

CARIUS'S  test,  3.  Caustic-alkali  test,  3.  Ignition  with 
sodium,  4. 

II.  THE  ALLOTROPIC  MODIFICATIONS  OF  CARBON  (16) 4 

Graphite,  4.  Wood-charcoal,  4.  Bone-charcoal,  4. 
Decolorization  of  solutions  by  bone-charcoal,  4. 
Absorption  of  lead  salts  by  bone-charcoal,  5.  De- 
odorizing action  of  bone-charcoal,  5. 

III.  LABORATORY  METHODS  (17-26) 5 

Fractional  distillation,  5.  Steam  distillation,  6.  Ex- 
traction with  solvents,  6.  Determination  of  the  melt- 
ing-point, 6.  Determination  of  the  boiling-point,  6. 
Crystallization,  7. 

IV.  SATURATED  HYDROCARBONS  (28-38) 7 

Preparation    of    methane,    7.  Distillation    of    petroleum, 

8.  Inflammability    of    petroleum- vapour,    8.     Stabil- 
ity of  the  saturated  hydrocarbons,  8. 

V.  ALCOHOLS,  CnH2n-t-i'OH  (39-50) 8 

Action  of  sodium  upon  alcohol,  8.     Fusel  oil,  9.     Wine, 

9.  Heat  developed  by  mixing  alcohol  and  water,  9. 
Tests  for  water  in  alcohol,   9.     Separation   of  water 
from  alcohol,  10.    Oxidation  of  ethyl  alcohol,  10. 

ix 


x  CONTENTS 

PAGB 

VI.  ALKTL  HALIDES,  ESTERS,  ETHERS,  AND  MERCAPTANS  (51-60) 10 

Ethyl  chloride,  10.  Ethylsulphuric  acid,  10.  Diethyl 
ether,  11.  Ethylmercaptan,  12. 

VII.  AMINES  AND  NITRO-COMPOUNDS  (61-70) 12 

Amines  (61-67) 12 

Methylamine,  12.  Carbylamine-reaction,  12.  Mustard- 
oil  reaction,  12.  Reaction  with  copper  salts,  13. 
Nitrous-acid  test,  13.  Nitrosoamines,  14.  Dimethyl- 
amine  and  trimethylamine,  14. 

Nitro-compounds  (68-70) 14 

Sodium  nitromethane,  14.  Nitrolic-acid  reaction,  14. 
Reduction  of  nitro-compounds,  14. 

VIII.  NlTRILES  AND  ISoNlTRILES  (76~78) 15 

Preparation,  15.     Hydrolysis  of  nitriles,  15. 

IX.  SATURATED  ACIDS,  CnH2nO2;  AND  ESTERS  (79-88;  91-95) 15 

Formic  acid,  15.  Decomposition  of  mercuric  formate, 
16.  Action  of  concentrated  sulphuric  acid  on  formic 
acid,  16.  Oxidation  of  formic  acid  by  potassium  per- 
manganate, 17.  Cacodyl-test  for  acetic  acid,  17. 
Stability  of  acetic  acid  towards  oxidizing  agents,  17. 
Silver  acetate,  17.  Test  for  acetic  acid,  18.  Oxidation 
of  ethyl  alcohol  to  acetic  acid,  18.  Action  of  caustic 
alkalis  on  sodium  acetate,  18.  Saponification  of  butter, 

18.  Calcium  and  lead  salts  of  the  higher  fatty  acids,  19. 
Volatile  fatty  acids,  19.     Higher  fatty  acids,  19.    Soap, 

19.  Emulsifying  action  of  soap,  20.     Cleansing  action 
of  soap,  20.     Ethyl  acetate,  20.     Velocity  of  saponifica- 
tion  of  ethyl  acetate,  20.     Solubility  of  ethyl  acetate  in 
water,  20. 

K.  ALDEHYDES  AND  KETONES  (98-111) 21 

Aldehydes  (98-109) 21 

Acetaldehyde,  21.  Silver-mirror  test,  21.  Aldehyde- 
resin,  21.  SCHIFF'S  reaction,  21.  Production  of 
formaldehyde,  22.  Action  of  formaldehyde  on  proteins, 
22.  Non-resinification  of  formaldehyde,  22. 

Ketones  (98-103,  110  and  111) 22 

Acetone,  22.  Test  for  acetone,  22.  Addition-product 
of  acetone  and  sodium  hydrogen  sulphite,  22.  Sepa- 
ration of  acetone  from  aqueous  solution,  23.  Oxida- 
tion of  acetone,  23. 


CONTENTS 


XI.  UNSATUEATED  HYDROCARBONS  (112-127) .  . . 23 

Olefines  (112-120) 23 

Ethylene,  23.  Luminosity  of  the  ethylene  flame,  23. 
Action  of  bromine  on  ethylene,  23.  VON  BAEYER'S 
test  for  the  double  bond,  24.  Explosive  mixture  of 
ethylene  and  oxygen,  24.  Unsaturated  hydrocarbons 
in  coal  gas,  24.  Double  linking  in  amylene,  24. 

Acetylene  (126) 24 

Preparation  of  acetylene,  24.  Copper  acetylene  and  sil- 
ver acetylene,  24. 

XII.  MONOBASIC  UNSATURATED  ACIDS  (134-138) 25 

Double  bond  in  almond  oil,  25.  Olei'c  acid  from  almond 
oil,  25.  Elai'dic  transformation,  25.  Fusion  of  oleic 
acid  with  caustic  alkali,  25.  Lead  oleate,  26. 

XIII.  CHLOROFORM  AND  IODOFORM  (144-146) 26 

Preparation  of  chloroform,  26.  Formation  of  chloroform 
from  trichloroacetic  acid,  26.  Action  of  potassium 
hydroxide  on  chloroform,  26.  Conversion  of  chloroform 
into  potassium  cyanide,  27.  Chloroform  and  silver 
nitrate,  27.  lodoform-test  for  alcohol,  27. 

XIV.  GLYCEROL  (151-155) 27 

Preparation  of  allyl  alcohol,  27.  Test  for  glycerol,  28. 
Action  of  alkalies  on  copper  salts  in  presence  of 
glycerol,  28. 

XV.  SATURATED  DIBASIC  ACIDS  (161-168) 28 

Oxalic  Acid  (162) 28 

Preparation  of  oxalic  acid  from  wood,  28.  Conversion 
of  formates  into  oxalates,  29.  Calcium,  lead,  and  cop- 
per oxalates,  29.  Decomposition  of  calcium  oxalate 
by  heat,  29.  Decomposition  of  lead  and  copper  oxa- 
lates by  heat,  29.  Action  of  concentrated  sulphuric 
acid  on  oxalic  acid,  29.  Complex  oxalates,  30.  Action 
of  light  on  EDER'S  solution,  30.  Dimethyl  oxalate,  30. 
Diethyl  oxalate,  31.  Oxamide,  31. 

Succinic  Acid  (166) 31 

Barium  succinate,  31.  Basic  ferric  succinate,  31.  Suc- 
cinimide,  31. 


xii  CONTENTS 

PAGS3 

XVI.  HYDROXY-ACIDS  OR  ALCOHOL-ACIDS  (179-197) 32 

Lactic  Acid  (182) 32 

Decomposition  of  lactic  acid  by  dilute  sulphuric  acid,  32. 
Decomposition  of  lactic  acid  by  concentrated  sulphuric 
acid,  32.  Oxidation  of  lactic  acid,  32. 

Tartaric  Acid  (188-196) 32 

Potassium  tartrates,  32.  Iron  ammonium  tartrate,  32. 
FEHLING'S  solution,  33.  Action  of  heat  on  tartaric 
acid,  33.  Microchemical  test  for  tartaric  acid  and  race- 
mica  cid,  33.  Relative  solubility  of  calcium  tartrate 
and  calcium  racemate,  33.  "  Tartar  emetic,"  33. 

Citric  Acid  (197) 33 

Preparation  from  lemons,  33.  Action  of  concentrated 
sulphuric  acid  on  citric  acid,  34. 

XVII.  CHLORAL  HYDRATE  (201) 34 

Action  of  water  on  chloral,  34.  Action  of  alkali  hydroxide 
on  chloral  hydrate,  34.  Silver-mirror  test  for  chloral 
hydrate,  35.  Action  of  sodium  hydrogen  sulphite  on 
chloral  hydrate,  35. 

XVIII.  ALDEHYDO-ALCOHOLS  AND  KETO-ALCOHOLS  OR  SUGARS  (202- 

228) 35 

Properties  of  the  Monoses  (203) 35 

Silver-mirror  test,  35.  Resinification  with  caustic  alkalies, 
35._Reduction  of  FEHLING'S  solution,  35.  Osazones,  35. 

Methods  of  Formation  of  the  Monoses  (206) 36 

Inversion  of  sucrose  (cane-sugar),  36.    Glycerose,  36. 

Pentoses  (207) 36 

Furfuraldehyde-test,  36. 

Hexoses  (208) 36 

Hydrochloric-acid  test,  36. 

Dextrose  (208) 37 

Calcium  alkoxide  of  dextrose,  37.  Glucosesulphuric  acid, 
37.  Copper  alkoxide  of  dextrose,  37.  Detection  of 
dextrose  in  urine,  37.  Oxidation  of  dextrose  by  nitric 
acid,  37. 

La3vulose  (209) 38 

Alcoholic  character,  38.     Test  for  bevulose,  38. 

d-Galactose  (211) 38 

Oxidation  of  d-galactose  to  mucic  acid,  38. 


CONTENTS 


Hexodioses  (213-220) 38 

Lactose  (215) £8 

Detection  of  lactose  in  milk,  38.  Lactosazone,  39. 
"  Sand-sugar,"  39. 

Sucrose  (216-220) 39 

Properties  distinguishing  sucrose  from  the  monoses,  39. 
Action  of  heat  on  sucrose,  39.  Tricalcium  saccharate, 

39.  Inversion,  39. 

Polyoses  (224-228) 40 

Starch  (225  and  226) 40 

Starch-paste,  40.  Properties  distinguishing  starch  from 
the  monoses,  40.  Conversion  of  starch  into  dextrose, 

40.  Iodine-test   for   starch,  40.      Barium   alkoxide   of 
starch,    40.     Conversion    of    starch    into    dextrin,    40. 
Potato-starch,  41. 

Cellulose  (227  and  228) 41 

Hydrolysis  of  cellulose,  41.  Parchment-paper,  41. 
Solubility  of  cellulose  in  SCHWEITZER'S  reagent,  41. 
Nitrocelluloses,  41.  Detection  of  lignin  in  paper,  42. 

XIX.  PROTEINS  (246-254) 42 

Detection  of  nitrogen  and  sulphur  in  the  proteins,  42. 
"  Salting-out  "  proteins  with  ammonium  sulphate,  42. 
Coagulation  of  proteins  by  alcohol,  42.  Coagulation 
of  proteins  by  nitric  acid,  43.  Biuret-reaction,  43. 
MILLON'S  reagent,  43.  Xanthoprotein-reaction,  43. 
ADAMKIEWICZ'S  reaction,  43.  Decomposition-products 
of  keratin,  43. 

XX.  HYDROCYANIC  ACID  AND  ITS  SIMPLE  AND  COMPLEX  SALTS  (256 

and  257) 43 

Hydrocyanic  acid,  43.  Prussian-blue  test,  44.  Silver 
cyanide,  44.  Hydrolysis  of  potassium  cyanide,  44. 
Conversion  of  ammonium  formate  into  hydrocyanic 
acid,  44.  Double  ferrocyanide  of  potassium  and  cal- 
cium, 44.  Ferrocyanic  acid,  44.  Action  of  concen- 
trated sulphuric  acid  on  potassium  ferrocyanide,  44. 
Action  of  heat  on  potassium  ferrocyanide,  45.  Potas- 
sium ferricyanide,  45.  Reduction  of  potassium  ferri- 
cyanide,  45.  Oxidation  of  potassium  ferrocyanide  by 
potassium  permanganate,  45. 


xiv  CONTENTS 

PAGE 

XXI.  POTASSIUM  CYANATE  AND  POTASSIUM  THIOCYANATE  (258-260). .     45 

Potassium  cyanate,  45.  Potassium  thiocyanate,  46. 
Silver  thiocyanate,  46. 

XXII.  DERIVATIVES  OF  CARBONIC  ACID  (263-270) 46 

Carbon  Disulphide  (264) 46 

Inflammability,   46.     Volatility,  46.     Solvent  power,  46. 
Barium   trithiocarbonate,   47.     Potassium   and   copper 
salts  of  xanthic  acid,  47. 
Urea  (266  and  267) 47 

WOHLER'S  synthesis,  47.  Urea  oxalate,  47.  Urea 
nitrate  from  urine,  47.  KNOP'S  method  for  the  esti- 
mation of  urea  in  urine,  48.  BUNSEN'S  method  for 
the  estimation  of  urea  in  urine,  48.  LIEBIG'S  method 
for  the  estimation  of  urea  in  urine,  48.  Action  of  heat 
on  urea,  48.  Cyanuric  acid,  48. 
Carbamic  Acid  (268) 49 

Calcium  carbamate,  49.     Ammonium  dithiocarbamate,  49. 

XXIII.  URIC  ACID  GROUP  (271-273) , 49 

Ammonium  urate,  49.  Di-potassium  urate,  49.  Mu- 
rexide-test  for  uric  acid,  49.  Reduction  of  silver 
nitrate  by  uric  acid,  50.  Murexide-test  for  caffeine,  50. 

XXIV.  BENZENE  AND  ITS  HOMOLOGUES  (281-288) 50 

Stability  of  benzene  towards  the  halogens,  50.  Absence 
of  double  bonds  in  benzene,  50.  Nitrobenzene,  50. 
Benzenemonosulphonic  acid.  50.  FRIEDEL  and  CRAFTS'S 
reaction,  51.  Formation  of  benzene  from  calcium  ben- 
zoate,  51.  Oxidation  of  side-chains,  51. 

XXV.  MONOHALOGEN  COMPOUNDS  (289) 51 

Stability  of  monochlorobenzene  towards  alcoholic  potash 
or  soda,  51. 

XXVI.  MONOHYDRIC  PHENOLS  (292-294) 52 

Preparation  of  phenol  from  calcium  salicylate,  52.  Prep- 
aration of  phenol  by  fusion  of  sodium  benzenesulphonate 
with  sodium  hydroxide,  52.  Sodium  phenoxide,  52. 
Tribromophenol,  52.  Ferric-chloride  test  for  phenol, 
52.  Depression  of  the  freezing-point  of  phenol,  53. 
Action  of  nitric  acid  on  phenol,  53,  Cresol,  53. 


CONTENTS  xv 

PAGB 

XXVII.  MONOAMINO-COMPOUNDS  AND  THEIR  DERIVATIVES  (296-301)  .       53 

Aniline,  53.  Neutral  reaction  of  aniline,  54.  Aniline 
salts,  54.  Tribromoaniline,  54.  Bleaching-powder  test 
for  aniline,  54.  Potassium-dichromate  test  for  ani- 
line, 54.  Acetoanilide,  54.  Carbylamine-reaction,  54. 
Diphenylamine,  54.  Nitrosodimethylaniline,  55. 
LIEBERM ANN'S  test  for  aromatic  nitroso-compounds, 

55.  Azobenzene,    hydrazobenzene,  and  benzidine  sul- 
phate, 55.     Diphenylurea,  55. 

XXVIII.  DlAZO-COMPOUNDS  AND  HYDRAZINES  (305-310) 56 

Benzenediazonium  chloride,  56.  Replacement  of  Nz- 
group  in  benzenediazonium  chloride  by  hydroxyl, 

56.  GATTERMANN'S  reaction,  56.     Diazoaminobenzene, 
56.  Aminoazobenzene,     56.     Oxidation     of    phenylhy- 
drazine  by  FEHLING'S  solution,  57. 

XXIX.  BENZOIC  ACID  AND  ITS  DERIVATIVES  (311-313) 57 

Benzonitrile  and  benzoic  acid,  57.  Benzo'ic  acid  from 
gum-benzoin,  57.  Volatility  of  benzoic  acid  with  steam, 

58.  Solubility  of  benzoic   acid  in  water,   58.     Ethyl 
benzoate,    58.     Benzanilide,    58.     Benzamide,    58. 

XXX.  BENZALDEHYDE  (314  and  315) 59 

Silver-mirror    test,     59.     Benzaldehydephenylhydrazone, 

59.  Sulphite  compound  of  benzaldehyde,  59.     Action 
of  alcoholic  potash  on  benzaldehyde,  59.     Oxidation  of 
benzaldehyde,  59. 

XXXI.  BENZENE  HOMOLOGUES  WITH  SUBSTITUTED  SIDE-CHAINS  (321- 

325) 60 

Saponification  of  benzyl  chloride  by  potassium  or  sodium 
hydroxide,  60.  Benzyl  iodide,  60.  Action  of  light  on 
toluene  in  presence  of  bromine,  60.  Resinification  of 
benzyl  alcohol,  60. 

XXXII.  COMPOUNDS  CONTAINING  AN  UNSATURATED  SIDE-CHAIN  (328)    61 

Oxidation  of  cinnamic  acid  by  potassium  permanganate,  61. 

XXXIII.  POLYSUBSTITUTED  BENZENE  DERIVATIVES  (329-350) 61 

Reactivity  of  the  halogen  atom  in  halogen  nitro-com- 
pounds,  61.  m-Dinitrobenzene,  61.  Reactivity  of 
one  nitro-group  in  1 :  3 :  5-trinitrobenzene,  61.  Nitro- 


XVI  CONTENTS 


phenols,  62.  Coloured  salts  of  p-nitrophenol,  62.  Picric 
acid,  62.  Potassium  picrate,  62.  Taste  of  picric  acid, 
62.  Dyeing  with  picric  acid,  62.  isoPurpuric  acid, 

62.  Chloropicrin,    62.     lonization    of    picric    acid    in 
aqueous  solution,  63.     Tests  for  catechol,  resorcinol,  and 
quinol,  63.     Reducing  power  of  the  dihydroxybenzenes, 

63.  Pyrogallol,  .63.     Benzoquinone,  64.     Quinhy drone, 

64.  Difference  in  basicity  of  the  three  nitroanilines,  64. 
Reactivity  of  the  amino-group  in  picramide,  64.     p-Dia- 
zobenzenesulphonic    acid,    64.     Oxidation    of    amino- 
phenols,  64.    Test  for  nitrous  acid  with  ra-phenylenedia- 
mine,  64.     Dyeing  with  aminoazobenzene,  65.     Reduc- 
tion of  aminoazobenzene,  65.     Taste  of  "  saccharin," 

65.  Salicylic  acid,   65.     Action  of  bromine- water  on 
salicylic  acid,  65.     Identification  of  salicylic  acid  and 
phenol,  65.     Calcium  salicylate,  65.     Manufacture  of 
ink,   65.     Action  of  tannin  on  gelatin,   66.     Test  for 
tannin,  66.     Action  of  tannin  on  quinine,  66.     Inter- 
action of  proteins  and  tannin,  66.     Decomposition  of 
anthranilic  acid,  66.     Phthalic  anhydride,  66.     Fluor- 
escein,    66.      Phenolphthalein,    66.      Red     anion     of 
phenolphthalein,  67. 

XXXIV.  HYDROCYLIC  COMPOUNDS  (365-370) 67 

Artificial  camphor,  67.  Volatility  of  camphor  with 
steam,  67.  Camphor  and  water,  67.  Camphoric 
acid,  67. 

XXXV.  BENZENE-NUCLEI  LINKED  TOGETHER  BY  CARBON  (371-374) .  .     68 

Rosolic  acid,  68.  Magenta,  68.  Action  of  concen- 
trated hydrochloric  acid  on  a  solution  of  magenta,  68. 
Colour-base,  68.  Leu  co-base,  68. 

XXXVI.  CONDENSED  BENZENE-NUCLEI  (377-386) 69 

Action  of  heat  on  naphthalene,  69.  Naphthalene 
picrate,  69.  Naphthalenemonosulphonic  acids,  69. 
a-Nitronaphthalene,  69.  Crude  naphthol,  69.  Mar- 
tius's  yellow,  70.  Naphthylamines,  70.  Congo-red,  70. 
Naphthionic  acid,  70.  Oxidation  of  anthracene  by  chro- 
mic acid,  70.  Test  for  anthraquinone,  70.  Potas- 
sium salt  of  alizarin,  70. 


CONTENTS 


xvii 


XXXVII.  HETEROCYCLIC  COMPOUNDS  (387-399) 71 

Pyridine,  71.  Action  of  pyridine  on  ferric  chloride,  71. 
Action  of  pyridine  on  mercuric  chloride,  71.  Test  for 
pyridine,  71.  Action  of  the  alkaloid-reagents  on  pyri- 
dine, 71.  Stability  of  pyridine  towards  VON  BAEYER'S 
reagent,  71.  Stability  of  pyridine  towards  oxidizing 
agents,  71.  Pyrrole-red,  71.  Indophenin-reaction,  71. 
Tests  for  antipyrine,  72. 

XXXVIII.  CONDENSATION-PRODUCTS  OF  BENZENE  AND  HETEROCYLIC 

NUCLEI  (400-405) 72 

SKRAUP'S  synthesis  of  quinoline,  72.  Quinoline  hydro- 
chloride,  72.  Quinoline  picrate,  72.  Quinoline  di- 
chromate,  73.  Volatility  of  indigo,  73.  Solubility  of 
indigo  in  nitrobenzene,  73.  Indigosulphonic  acid,  73. 
Oxidation  of  indigo  to  isatin,  73.  "Vat-dyeing,"  73. 

XXXIX.  ALKALOIDS  (406-415) 73 

Alkaloid-reagents,  73.  Nicotine,  73.  Fluorescence  of 
quinine-sulphate  solution,  74.  Action  of  chlorine  on 
quinine  salts,  74.  Test  for  strychnine,  74.  Test  for 
brucine,  74. 

INDEX 75 


A    LABORATORY    MANUAL    OF 
ORGANIC  CHEMISTRY. 


I.     QUALITATIVE   ANALYSIS    OF    CARBON   COMPOUNDS. 

(3-5.) 
DETECTION   OF   CARBON   AND   HYDROGEN  (3). 

1.  Carbonization. — A  small  quantity  of  sugar  is  heated  in  a 
crucible  covered  with  a  lid.     Inflammable  gases  are  evolved, 
leaving  a  residue  of  charcoal.     This  is  proved  to  be  carbon 
by  heating  it  in  a  hard-glass  tube  about  15  cm.  long  sealed 
at  one  end,  and  slightly  inclined,  the  tube  being  first  filled 
with   oxygen,   and   closed  with   a  loosely-fitting   cork.     Car- 
bon dioxide  is  formed,  part  remaining  in  the  tube.     After 
cooling,   lime-water  is  agitated  with  the   gas,   and  becomes 
turbid  owing  to  the  formation  of  calcium  carbonate,  CaCOs. 

The  presence  of  carbon  in  coal-gas  is  shown  by  the  soot 
deposited  when  a  cold  surface,  such  as  that  of  a  porcelain 
crucible-lid,  is  introduced  into  a  luminous  flame. 

2.  Oxidation  with  Copper  Oxide. — 10  g.  of  finely-powdered 
copper  oxide — a  hygroscopic  substance — are  dried  by  heat- 
ing in  a  dish  or  crucible.     While  still  warm  it  is  mixed  care- 
fully with  a  small  quantity  of  sugar,  and  the  mixture  placed 
in  a  hard-glass  tube  sealed  at  one  end;   the  open  end  of  the 
tube  is  then  closed  with  a  cork,  and  a  delivery-tube  leading 
into  lime-water.     On  heating,  the  sugar  is  oxidized  by  the 


2      LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY      [i. 

copper  oxide;  the  carbon  dioxide  evolved  makes  the  lime- 
water  turbid,  and  the  water  formed  condenses  in  drops  on  the 
cool  part  of  the  tube. 

DETECTION   OF   NITROGEN  (4). 

3.  a)  LASSAIGNE'S  Method. — A  piece  of  dried  albumin — a 
substance  containing  nitrogen — and  a  piece  of  sodium  are 
placed  in  a  narrow  tube  sealed  at  one  end.  The  tube  is  then 
gradually  heated  to  redness,  and  maintained  at  this  tem- 
perature for  a  few  minutes.  The  hot  end  of  the  tube  is  placed 
in  2-3  c.c.  of  water,  whereupon  it  cracks,  and  the  sodium 
cyanide  formed  dissolves.  After  filtering  through  a  small 
filter-paper,  and  washing  the  residue  with  a  few  drops  of 
water,  a  drop  of  a  solution  containing  iron  in  the  ferrous  and 
ferric  state  is  added  to  the  filtrate,  and  the  mixture  acidified 
slightly  with  hydrochloric  acid  to  dissolve  the  precipitated  fer- 
rous and  ferric  hydroxides.  If  sodium  cyanide  was  present, 
there  remains  a  blue  precipitate,  due  to  the  formation  of 
Prussian  blue. 

6)  WILL  and  VARRENTRAP'S  Method. — Small  pieces  of  dry 
albumin  are  mixed  with  five  times  their  bulk  of  soda-lime,  and 
the  mixture  warmed  in  a  test-tube.  A  strip  of  moist,  red 
litmus-paper  held  at  the  open  end  of  the  tube  is  turned  blue  by 
the  evolved  ammonia,  and  the  characteristic  odour  of  the 
gas  can  also  be  detected. 

c)  KJELDAHL'S  Method. — 0- 1  g.  of  acetamide  is  heated  with 
2  c.c.  of  concentrated  sulphuric  acid  in  a  test-tube.  After  a 
short  interval,  the  reaction-mixture  is  poured  carefully  into 
25  c.c.  of  water,  excess  of  sodium  hydroxide  added,  and  the 
beaker  covered  with  a  glass  plate  having  a  moistened  strip  of 
red  litmus-paper  adhering  to  its  lower  surface.  In  a  few 
minutes  the  litmus  is  turned  blue  by  the  evolved  ammonia. 


i.]     QUALITATIVE  ANALYSIS  OF  CARBON  COMPOUNDS     3 
DETECTION   OF  THE  HALOGENS   (5). 

4.  a)  BEILSTEIN'S   Test. — Copper  oxide  is  introduced  into 
a  loop  at  the  end  of  a  piece  of  platinum-wire  by  dipping  the 
moistened    loop   into  finely-powdered  copper    oxide,    heating 
in  the  flame,  and  repeating  these  operations  several  times. 
A  piece  of  copper-oxide  wire  held  by  the  platinum-wire  can 
also  be  used.     The  copper  oxide  is  then  heated  to  redness 
until  the  flame  is  no  longer  coloured,  cooled,  moistened  with  a 
drop  of  chloroform,  CHCls,  by  the  aid  of  a  capillary  pipette, 
and  again  introduced  into  the  flame.    The  vapour  of  the  copper 
halide  (chloride)  formed  imparts  a  fine  green  colour  to  the  flame. 

6)  Calcium-oxide  Test. — A  lump  of  quicklime  is  heated  in  a 
test-tube  to  a  high  temperature,  and,  while  still  hot,  two  drops 
of  chloroform  are  added.  When  cold,  the  contents  of  the 
tube  are  treated  with  water,  and  the  lime  dissolved  by  dilute 
nitric  acid  free  from  hydrochloric  acid.  On  addition  of  silver 
nitrate  to  this  solution,  a  precipitate  of  silver  chloride  is 
obtained,  proving  the  presence  of  chlorine  iir  the  chloroform. 

Chloroform  is  agitated  with  silver-nitrate  solution,  but 
no  precipitate  of  silver  chloride  is  formed. 

DETECTION    OF   SULPHUR  (5). 

5.  a)  CARIUS'S  Test. — 0*1   g.   of  ammonium  thiocyanate, 
NHUCNS,  is  warmed  with  5  c.c.  of  nitric  acid  of  1*2  specific 
gravity  till  the  reaction  begins;   to  prevent  the  oxidation  be- 
coming too  violent,  the  heating  is  then  discontinued.     After 
dilution  of  the  cold  solution  with  25  c.c.  of  water,  barium 
chloride  is  added,  the  resulting  white  precipitate  of  barium 
sulphate  indicating  that  the  sulphur  has  been  oxidized  to 
sulphuric  acid. 

6)  Caustic-alkali  Test. — A  small  quantity  of  egg-albumin 
is  warmed  with  a  concentrated  solution  of  sodium  hydroxide 
(1  :  2),  in  which  it  dissolves,  forming  sodium  sulphide  among 
the  products.  This  can  be  proved  either  by  adding  a  few 


4       LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY       [n. 

drops  of  lead  acetate,  resulting  in  the  formation  of  black  lead 
sulphide,  PbS;  or  by  bringing  a  drop  of  the  liquid  into  con- 
tact with  a  bright  silver  coin,  with  production  of  a  brownish- 
black  stain  of  silver  sulphide,  Ag2S;  or  by  addition  of  two 
or  three  drops  of  a  solution  of  sodium  nitroprusside  to  the 
alkaline  mixture,  when  a  deep-violet  coloration  results,  some 
minutes  elapsing  before  the  colour  attains  its  maximum 
intensity.  Traces  of  sulphur  can  be  detected  by  this  reaction, 
c)  Ignition  with  Sodium. — A  piece  of  albumin  is  ignited 
with  sodium  as  described  in  3,  a,  and  the  hot  tube  placed  in 
water.  After  filtration,  the  presence  of  sodium  sulphide  in 
the  solution  can  be  detected  by  means  of  lead  acetate  or 
sodium  nitroprusside  (5,  b). 

II.    THE   ALLOTROPIC   MODIFICATIONS    OF    CARBON. 

(16.) 

1.  Graphite. — 0*1   g.   of  graphite  is    mixed  with  5  g.  of 
finely-powdered    copper   oxide,    and   heated   to   a   high   tem- 
perature in  the  apparatus  described  in  I.,  2.      The  evolved 
carbon  dioxide  renders  the  lime-water  turbid. 

2.  Wood-charcoal. — A    piece    of   wood-charcoal    is     gently 
heated  in  a  test-tube;   the  water  occluded  in  the  pores  of  the 
charcoal  'evaporates,  and  condenses  in  drops  on  the  cool  parts 
of  the  tube. 

A  piece  of  wood-charcoal  is  placed  in  water,  and  the  mixture 
warmed.  The  air  present  in  the  pores  of  the  charcoal  escapes, 
forming  bubtles  in  the  water. 

3.  Bone-charcoal. — Pieces  of  bone  are  placed  in  a  crucible 
fitted  with  a  lid,  and  heated  in  a  fume-cupboard.     Vapours  of 
disagreeable  odour  are  evolved,  the  residue  in  the  crucible 
consisting  of  bone-charcoal  and  the  mineral  constituents  of 
the  bones.     The  bone-ash  is  freed  from  mineral  matter  by 
heating  the  residue  with  hydrochloric  acid. 

4.  Decolorization  of  Solutions  by  Bone-charcoal. — 20  c.c.  of 
a  very  dilute  solution  of  magenta — a  red  dye — are  agitated 


in.]  LABORATORY  METHODS  5 

with  a  teaspoonful  of  bone-charcoal,  and  filtered.     The  filtrate 
is  colourless  ("  Inorganic  Chemistry/'  176). 

5.  Absorption  of  Lead  Salts  by  Bone-charcoal. — 20  c.c.  of  a 
very  dilute  solution  of  lead  acetate  are  tested  for  lead  by 
addition  of  an  aqueous  solution  of  hydrogen  sulphide.     The 
solution  must  be  so  dilute  that  it  gives  a  brown  turbidity, 
but  no  precipitate. 

A  like  volume  of  the  lead-acetate  solution  is  agitated  for  a 
short  time  with  a  teaspoonful  of  bone-charcoal,  and  then 
filtered.  On  addition  of  hydrogen  sulphide  solution,  no 
turbidity  or  brown  coloration  is  developed  in  the  filtrate  ("  In- 
organic Chemistry,"  176). 

6.  Deodorizing  Action  of  Bone-charcoal. — A  dilute  aqueous 
solution  of  hydrogen   sulphide,   having   a  perceptible   odour 
of  the  gas,  is  agitated  with  bone-charcoal,  and  filtered.     An 
odourless  filtrate  is  obtained. 

III.     LABORATORY   METHODS. 
(17-26.) 

i.  Fractional  Distillation. — 50  c.c.  of  90  per  cent,  alcohol 
diluted  with  50  c.c.  of  water  are  placed  in  a  100  c.c.  fraction- 
ating-flask  fitted  with  a  thermometer  and  connected  with  a 
condenser,  and  gently  heated  with  a  small  flame.  The  liquid 
begins  to  boil  about  78°,  and  the  distillate  is  collected  in  two 
fractions,  the  first  passing  over  below  88°,  and  the  second 
above  that  temperature.  After  the  distillation  is  complete 
the  first  fraction  is  returned  to  the  flask,  and  slowly  distilled 
till  the  thermometer  again  reaches  88°.  The  burner  is  then 
removed,  the  second  fraction  poured  back  into  the  flask, 
and  the  distillation  continued  without  changing  the  receiver 
till  the  temperature  has  again  risen  to  88°.  A  different 
receiver  is  now  employed,  and  the  process  continued  till  dis- 
tillation is  complete. 

The  first  fraction  contains  most  of  the  alcohol,  and  can  be 
ignited;  the  second  is  chiefly  water,  and  is  incombustible. 


6        LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY     [m. 

2.  Steam  Distillation. — 10  c.c.  of  petroleum  are  placed  in  a 
200-c.c.   flask  d   (22,   Fig.    17)   connected  with    a  condenser. 
Water  is  boiled  in  the  can  a,  which  is  fitted  with  a  safety- 
tube  b  and  a  delivery-tube  c,  the  evolved  steam  being  passed 
into  the  flask  d  through  a  glass  tube  reaching  to  the  bottom, 
and  bent  as  in  the  illustration.     The  flask  is  inclined  at  an 
angle  to  prevent  the  petroleum  being  carried  over  mechanically. 
The  distillate  is  a  mixture  of  petroleum  and  water. 

3.  Extraction   with   Solvents. — 10  c.c.  of   a   five   per   cent, 
solution  of  urea  and  10  c.c.  of  ether  are  introduced  into  a  sepa- 
rating-funnel,  and  the  mixture  vigorously  shaken.     When  the 
liquid  has  separated  into  two  layers,  these  are  removed,  and 
each  is  evaporated  to  dryness  in  a  porcelain  dish  on  the  water- 
bath.     Only  a  trace  of  urea  is  obtained  from  the  ether,  this 
substance  being  very  soluble  in  water,  and  almost  insoluble 
in  ether. 

A  saturated  solution  of  salicylic  acid  is  prepared  by  vigor- 
ously agitating  1  g.  of  the  acid  with  25  c.c.  of  water,  and  filter- 
ing. The  filtrate  is  extracted  with  10  c.c.  of  ether  as  described 
in  the  last  paragraph.  Almost  all  the  salicylic  acid  dissolves 
in  the  ether,  being  very  soluble  in  this  solvent,  and  but  slightly 
soluble  in  water. 

4.  Determination  of  the  Melting-point. — A  little  naphthalene 
is  placed  in  a  narrow  glass  tube   sealed   at  one   end,  several 
of  these  being  obtained  by  drawing  out  a  test-tube.     The 
capillary  tube  is  fastened  with  an  india-rubber  ring  to  the 
stem  of  a  thermometer,  so  that  the  part  containing  the  naphtha- 
lene is  about  half-way  up  the  mercury  bulb.     The  end  of  the 
thermometer  carrying  the  tube  is  then  immersed  in  a  melting- 
point  flask  or  beaker  containing  water,  which  is  slowly  heated 
with  a  small  flame.     When  the  substance  melts,   the  tem- 
perature (80°)  of  the  thermometer  is  observed. 

5.  Determination    of    the    Boiling-point. — A   small  quantity 
of  benzene  is  placed  in  a  fractionating-flask  having  a  high 
side-tube  connected  with  a  condenser.  The  flask  is  closed  with 


iv.]  SATURATED  HYDROCARBONS  7 

a  cork  fitted  with  a  thermometer,  the  bulb  being  placed  sev- 
eral centimetres  below  the  side-tube.  The  benzene  is  heated 
with  a  small  flame  to  ebullition,  and  the  temperature  at 
which  the  mercury  becomes  stationary  noted.  This  is  the 
boiling-point. 

6.  Crystallization. — 3  g.  of  crude  oxalic  acid  are  dissolved 
in  10  c.c.  of  hot  water,  and  the  impurities  present  in  the  acid 
removed  by  filtering  the  turbid  solution.  On  standing,  the 
clear  filtrate  deposits  crystals  of  oxalic  acid.  The  mother- 
liquor  is  poured  off,  the  crystals  are  drained  on  a  funnel,  and 
dried  on  a  porous  plate  or  between  sheets  of  filter-paper. 

IV.    SATURATED  HYDROCARBONS. 
(28-38.) 

i.  Preparation  of  Methane,  CH4. — 5  g.  of  aluminium  carbide 
are  placed  in  a  fractionating-flask,  and  covered  with  100  c.c. 
of  water.  The  mouth  of  the  flask  is  then  closed  with  a  cork, 
and  the  methane  evolved  through  the  side-tube  collected 
in  thick-walled  cylinders.  One  of  these  cylinders  is  closed 
with  a  glass  plate,  and  turned  mouth  upwards.  On  removal 
of  the  cover,  and  ignition  of  the  gas  with  a  burner  or  taper, 
it  burns  with  a  flame  of  feeble  luminosity.  When  combus- 
tion ceases,  some  lime-water  is  poured  quickly  into  the  cylinder, 
the  cover  replaced,  and  the  contents  agitated.  The  carbon 
dioxide  formed  by  the  combustion  of  the  gas  renders  the  lime- 
water  turbid. 

A  thick-walled  explosion-cylinder  is  filled  about  one-third 
full  with  methane,  and  the  remainder  with  oxygen.  On  igni- 
tion, the  mixture  explodes  with  a  loud  report. 

A  cylinder  is  filled  with  chlorine  by  downward  displace- 
ment, and  over  it  is  placed  an  inverted  cylinder  full  of  methane, 
closed  with  a  glass  plate.  The  plate  is  removed,  and  the  gases 
mixed  by  inverting  the  cylinders  several  times,  care  being  taken 


8       LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY      [v. 

to  prevent  loss.  After  insertion  of  two  glass  plates  between 
the  cylinders,  one  is  placed  mouth  downwards  in  a  saturated 
solution  of  common  salt,  and  the  cover  removed.  In  diffused 
daylight  the  liquid  slowly  rises,  the  colour  of  the  chlorine  dis- 
appears, and  oily  drops  of  the  substitution-products — methyl- 
ene  chloride,  CH^Ck;  chloroform,  CHCls;  and  carbon  tetra- 
chloride,  CCU — are  deposited  on  the  sides  of  the  cylinder. 
The  mixture  must  not  be  exposed  to  direct  sunlight,  or  there  is 
danger  of  an  explosion.  On  ignition  of  the  contents  of  the 
other  cylinder,  hydrochloric  acid  is  produced,  and  soot  de- 
posited. 

2.  Distillation  of  Petroleum. — Petroleum  is  distilled  g lowly 
from   a  flask  connected  with  a  condenser  and  fitted  v/ith  a 
thermometer.     The  boiling-point  rises  gradually,  proving  the 
liquid  to  be  a  mixture. 

3.  Inflammability  of  Petroleum- vapour. — 5  c.c.  of  petroleum 
are  poured  into  a  porcelain  dish.     A  lighted  match  plunged 
into  the  liquid  is  extinguished.     If,  however,  the  petroleum 
is  carefully  heated  to  40°  on  a  water-bath,  the  inflammable 
vapour  evolved  is  ignited  by  the  application  of  a  burning 
match. 

4.  Stability    of    the    Saturated    Hydrocarbons. — Samples  of 
petroleum  and  of  paraffin-wax  are  agitated  with  concentrated 
sulphuric    acid    and    with    concentrated    nitric    acid.     Being 
mixtures  of  saturated  hydrocarbons,  they  are  neither  acted 
on  nor  dissolved. 


V.    ALCOHOLS,  CnH2n+1- OH. 
(39-50.) 

i.  Action  of  Sodium  upon  Alcohol. — 0-5  g.  of  sodium  is  intro- 
duced into  a  small  fractionating-flask  containing  10  c.c.  of 
absolute  alcohol,  and  fitted  with  a  delivery-tube  for  collecting 
gas  over  water.  The  mouth  of  the  flask  is  immediately  closed 


v.]  ALCOHOLS,  CnH2n+i-OH  9 

with  a  cork,  and  an  energetic  evolution  of  gas  takes  place. 
The  gas  is  collected  in  a  cylinder,  and  proved  by  ignition  to  be 
hydrogen. 

2.  Fusel-oil. — A  small  quantity  of  crude  spirit  is  evaporated 
slowly  on  a  water-bath.     After  the  volatilization  of  the  ethyl 
alcohol,  the  odour  of  fusel-oil  is  very  marked.  ,  It  is  also  per- 
ceptible when  a  few  drops  of  the  spirit  are  placed  on  the  palm 
of  the  hand,  and  rubbed  with  the  finger  to  promote  the  evapo- 
ration of  the  ethyl  alcohol. 

3.  Wine. — 25   c.c.   of  wine   contained  in  a   fractionating- 
flask  connected  with  a  condenser  are  heated  on  a  water-bath. 
Alcohol   distils,    and   can   be   recognized   by   its   odour   and 
inflammability. 

4.  Heat  Developed  by  Mixing  Alcohol  and  Water. — 10  c.c. 
of  absolute  alcohol  and  10  c.c.  of  water  are  poured  into  two 
small  beakers,  and  these  immersed  in  a  large  vessel  of  water 
to  bring  them  to  the  same  temperature.     This  is  noted,  and 
after  removal  of  the  beakers  from  the  water  their  contents 
are  mixed  quickly  and  stirred  with  the  thermometer.     A  rise 
in  temperature  is  observed. 

5.  Tests  for  Water  in  Alcohol. — a)  Copper-sulphate  Test. — 
3  g.  of  blue    crystallized   copper  sulphate,  CuS04,5H2O,  are 
gently  heated  in  a  porcelain  crucible  till  anhydrous,  the  salt 
being  converted  into  a  white  powder.     When  cold,  the  residue 
is  transferred  to  a  test-tube  or  small  flask  containing  15  c.c. 
of  aqueous  alcohol;  the  copper  sulphate  soon  regains  its  original 
blue  colour,  on  account  of  the  formation  of  the  hydrated  salt, 
CuS04,5H20. 

6)  CRISMER'S  Test. — 2  c.c.  of  petroleum  are  added  to  a 
like  volume  of  alcohol  of  about  90  per  cent,  strength,  and  a 
thermometer  is  introduced  into  the  liquid.  At  first,  the  two 
liquids  do  not  mix  completely,  but  the  application  of  slight 
heat  renders  them  wholly  miscible.  The  liquid  is  allowed 
to  cool,  and  the  temperature  is  noted  at  the  moment  of 
appearance  of  turbidity.  One  drop  of  water  is  then  added, 


10      LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY     [vi. 

and  the  liquid  again  heated  until  it  becomes  homogeneous. 
On  cooling,  turbidity  reappears  at  a  temperature  some  degrees 
higher  than  on  the  first  occasion. 

6.  Separation  of  Water  from  Alcohol. — Alcohol  of  about  50 
per  cent,  strength  is  agitated  with  solid  potassium  carbonate, 
and,  if  enough  of  the  salt  has  been  added,  two  layers  are 
obtained.     These  are  separated   by  means  of  a  tap-funnel. 
The  upper  layer  is  strong  alcohol,  and  burns  on  ignition;   the 
lower  layer  is  a  concentrated,  aqueous  solution  of  potassium 
carbonate,  containing  only  a  trace  of  alcohol. 

7.  Oxidation  of  Ethyl  Alcohol. — Ethyl  alcohol  is  heated  with 
an   aqueous   solution   of  potassium   permanganate   until  the 
violet  colour  has  disappeared  and  manganese  dioxide  has  been 
precipitated.     On  acidifying  the  mixture  with  sulphuric  acid 
and  distilling,  an  acid  distillate  with  an  odour  of  acetic  acid  is 
obtained. 

The  iodoform-test  for  ethyl   alcohol   is   given  in  XIII.,  6; 
the  benzoate-test  in  XXIX.,  5. 


VI.    ALKYL     HALIDES,     ESTERS,     ETHERS,     AND     MER- 

CAPTANS. 

(51-60.) 

1.  Ethyl  Chloride. — A  mixture  of  10  c.c.  of  alcohol  and  5  c.c. 
of  concentrated  sulphuric  acid  is  added  to  5  g.  of  common  salt 
contained  in  a  50-c.c.   fractionating-flask   connected  with  a 
condenser  in  a  fume-cupboard.     On  warming,  gaseous  ethyl 
chloride,  C2H5C1,  is  evolved,  and  dissolves  in  the  condensed 
alcohol.     When   ignited,   this   distillate  burns  with  a   green- 
tinged  flame — a  phenomenon  characteristic  of  many  chlorine 
derivatives. 

2.  Ethylsulphuric   Acid. — About  2  c.c.  of  concentrated  sul- 
phuric acid  are  poured  carefully  into  an  equal  volume  of  absolute 
alcohol,  the  mixing  being  accompanied  by  rise  of  temperature. 


vi.]  ALKYL  HALIDES,  ESTERS,  ETHERS,  ETC.  11 

The  mixture  is  heated  gently  for  a  short  time,  cooled,  and  poured 
into  25  c.c.  of  water.  This  solution  is  stirred,  and  barium 
carbonate  added  till  the  liquid  is  no  longer  acid  to  litmus. 
Carbon  dioxide  is  evolved,  with  formation  of  insoluble  barium 
sulphate  and  soluble  barium  ethylsulphate,  Ba^HsSO^. 
After  filtering,  dilute  sulphuric  acid  is  added  to  a  portion  of 
the  filtrate;  the  precipitate  of  barium  sulphate  formed  proves 
the  presence  of  a  barium  salt  in  solution. 

On  warming  the  rest  of  the  filtrate  with  dilute  hydrochloric 
acid,  barium  sulphate  is  precipitated.  This  is  due  to  the 
decomposition  of  the  liberated  ethylsulphuric  acid  into  alcohol 
and  sulphuric  acid,  followed  by  the  interaction  of  the  latter 
with  the  barium  ions  present  in  the  solution. 

3.  Diethyl  Ether,  (C2H5)2O. — A  fractionating-flask  is  fitted 
with  a  cork  carrying  a  tap-funnel  and  a  thermometer,  both 
arranged  nearly  to  touch  the  bottom.  After  50  c.c.  of  alcohol 
of  ninety  per  cent,  strength  and  50  c.c.  of  concentrated  sul- 
phuric acid  have  been  poured  into  the  flask,  5  g.  of  anhydrous 
aluminium  sulphate  are  added,  and  the  flask  is  connected  to 
a  condenser  with  a  rapid  current  of  water  flowing  through  its 
jacket.  Heat  is  then  applied  till  the  thermometer  indicates 
a  temperature  between  130°  and  140°.  As  soon  as  the  dis- 
tillation of  ether  begins,  alcohol  is  introduced  slowly  into  the 
flask  from  the  tap-funnel,  and  the  distillation  continued  with  a 
small  flame  so  as  to  maintain  the  temperature  constant.  The 
distillate  is  agitated  in  a  separating-funnel  with  a  like  volume 
of  wrater,  which  dissolves  most  of  the  alcohol,  leaving  a  layer 
of  ether  floating  on  the  surface  of  the  solution.  After  separa- 
tion from  the  aqueous  liquid,  the  ether  is  dried  by  agitation 
for  a  few  minutes  with  fused  and  finely-powdered  calcium 
chloride. 

A  small  quantity  of  the  ether  is  agitated  with  a  large  excess 
of  water,  in  which  it  dissolves. 

A  mixture  of  5  c.c.  of  ether  and  5  c.c.  of  water  is  shaken  in  a 
separating-funnel,  and  the  ethereal  and  aqueous  layers  sepa- 


12     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY    [vn. 

rated  carefully.  Anhydrous  copper  sulphate  added  to  this 
ether  turns  blue,  proving  that  the  ether  has  dissolved  some  of 
the  water.  On  gently  warming  the  aqueous  layer  in  a  por- 
celain dish,  ether-vapour  is  evolved,  and  can  be  recognized 
by  its  odour  and  by  its  combustion  with  a  bright,  luminous 
flame.  This  proves  that  the  water  has  dissolved  some  of  the 
ether. 

The  absorption  of  heat  caused  by  the  evaporation  of  ether 
can  be  demonstrated  by  placing  a  small  quantity  in  the  palm  of 
the  hand,  and  blowing  on  it.  A  sensation  of  cold  is  felt  imme- 
diately. 

4.  Ethylmercaptan. — On  warming  2  c.c.  of  a  saturated 
solution  of  potassium  ethylsulphate  with  a  like  volume  of  a 
thirty-three  per  cent,  solution  of  potassium  hydrogen  sul- 
phide, KHS,  the  odour  of  ethylmercaptan  at  once  becomes 
perceptible. 


VII.    AMINES  AND  NITRO-COMPOUNDS. 
(61-70.) 

AMINES  (61-67). 

1.  Methylamine. — A  thin  paste  of  bleaching-powder  is  ren- 
dered strongly  alkaline  by  addition  of  slaked  lime,  and  mixed 
with  an  aqueous  solution  of  5  g.  of  acetamide,  CH3-CONH2. 
On  distillation,  an  aqueous  solution  of  methylamine,  CH3'NH2, 
is  obtained  (259). 

2.  Carbylamine-Reaction. — A  portion  of  the   solution  thus 
obtained  is  warmed  gently  with  one  or  two  drops  of  chloroform 
and  a  small  quantity  of  alcoholic  potash.     Owing  to  the  forma- 
tion of  methylcarbylamine,  CHs-NC,  the  odour  characteristic 
of  i'sonitriles  is  perceived  (77). 

3.  Mustard-oil  Reaction. — A  mixture  of  carbon  disulphide 
and  absolute  alcohol  in  like  proportions  is  added  to  another 


VII.] 


AMINES  AND  NITRO-COMPOUNDS 


13 


portion  of  the  distillate  obtained  in  i,  till  solution  is  com- 
plete, and  the  liquid  is  warmed  for  a  short  time.  On  addi- 
tion of  ferric  chloride,  a  black  precipitate  of  sulphide  of  iron  is 
formed;  and,  on  further  heating,  the  odour  of  .methyl-mustard- 
oil,  CH3'NCS,  becomes  perceptible  (260). 

4.  Reaction  with  Copper  Salts. — The  remainder  of  the  dis- 
tillate of  i  is  added  drop  by  drop  to  1  c.c.  of  a  dilute  solution 
of  copper  sulphate.     At  first  a  precipitate  of  copper  hydroxide 
is  formed,  and  on  further  addition  of  the  amine-solution  redis- 
solves,  with  production  of  a  deep-blue  colour.     The  reaction, 
therefore,  is  analogous  to  that  between  ammonium  hydroxide 
and  copper  salts  ("  Inorganic  Chemistry/'  244). 

5.  Nitrous-acid  Test. — A  concentrated  aqueous  solution  of 
1  g.  of  ethylamine  hydrochloride,  C2H5NH2,HC1,  and  1  g.  of 


NITROUS  ACID  TEST  FOR  PRIMARY  AMINES. 


potassium  or  sodium  nitrite  is  poured  slowly  through  a  thistle- 
funnel  into  a  50-c.c.  fractionating-flask  a,  containing  20  c.c. 
of  glacial  acetic  acid  (Fig.).  The  evolved  nitrogen  is  freed 
from  ethyl  nitrite  by  passing  it  through  a  small  wash-bottle 
6,  containing  alcoholic  potash.  The  gas  is  collected  over  water 
in  a  cylinder  c,  and  proved  to  be  nitrogen  by  its  extinguishing 
a  lighted  wood-splint  or  taper.  By  means  of  the  iodoform- 


14     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY     [vn. 

test  (XIII.,  6),  the    presence  of  alcohol    in  the  fractionating- 
flask  can  be  shown. 

6.  Nitrosoamines. — To  a  cold,  saturated,  aqueous  solution  of 
1  g.  of  potassium  or  sodium  nitrite  is  added  1  g.  of  solid  diethyl- 
amine  hydrochloride,  (C2H5)2NH,HC1,  and  one  drop  of  dilute 
sulphuric  acid.     On  gently  heating  the  liquid,  diethylnitroso- 
amine,  (X^Hs^N-NO,  collects  on  the  surface  as  a  yellow  oil 
of  characteristic  odour. 

7.  Dimethylamine  and  Trimethylamine. — A  small  quantity  of 
sodium-hydroxide  solution  is  added  to  herring-brine  contained 
in  a  distilling-flask  connected  with  a  condenser.     On  heating,  a 
distillate  is  obtained;  this  is  alkaline,  owing  to  the  presence  of 
dimethylamine  and  trimethylamine.     Like  ammonium  hydrox- 
ide, it  precipitates  ferric  hydroxide,  Fe203,nH20,  from  a  solu- 
tion of  ferric  chloride. 

NITRO-COMPOUNDS  (68-70.) 

1.  Sodium    Nitromethane. — A  solution  of  3  drops  of  nitro< 
methane  in  1  c.c.  of  absolute  alcohol  is  prepared.     To  this  are 
added  a  few  drops  of  a  solution  of  sodium  ethoxide,  obtained 
by  dissolving  small  pieces  of  sodium  in  10  c.c.  of  absolute 
alcohol.     The   white   precipitate   of   sodium   nitromethane   is 
filtered   off,    and,  while   still   moist,    is   dissolved   in  a  small 
quantity  of  water.     It  must  not  be  dried  or  a  dangerous  explo- 
sion may  result.     When  moist,  it  is  innocuous. 

2.  Nitrolic-acid    Reaction. — The     liquid    thus    obtained    is 
mixed  with  a  few  drops  of  a  concentrated  aqueous  solution  of 
sodium  nitrite,   and  carefully  acidified  with  dilute  sulphuric 
acid.     The  blood-red  colour  of  the  sodium  salt  of  methyl- 
nitrolic  acid  is  produced.     It  is  discharged  by  adding  more 
acid,  but  returns  on  addition  of  a  dilute  solution  of  sodium 
hydroxide. 

3.  Reduction  of  Nitro-compounds. — 3  drops  of  nitromethane 
are  added  to   potassium-hydroxide    solution  and  granulated 


UULLtGt 

of   PHARMACY 

ix.]  SATURATED  ACIDS,  CnH2nO2;  AND  ESTERS  15 

zinc  contained  in  a  test-tube.  The  characteristic  odour  of 
methylamine  at  once  becomes  perceptible,  and  a  strip  of  red 
litmus-paper  held  in  the  vapour  is  turned  blue. 

VIII.    NITRILES  AND  zsoNITRILES. 

(76-78.) 

1.  Preparation. — A  mixture    of    10  g.  01  potassium  ethyl- 
sulphate  and  10  g.  of  dried  potassium  ferrocyanide  is  sub- 
mitted to  dry  distillation  in  a  retort  connected  with  a  con- 
denser.    The  distillate  has  the  isonitrile  odour,   due  to  the 
presence  of  ethylcarbylamine.     Agitation  with  dilute  sulphuric 
acid  for  a  short  time  removes  this   smell,  whereupon  that  of 
the    nitrile — propionitrile — formed    in    the    reaction    becomes 
perceptible,  although  it  was  previously  wholly  masked  by  that 
of  the  isonitrile,  a  by-product. 

2.  Hydrolysis  of  Nitrile s. — The  liquid  of  i  is  made  alkaline 
with  potassium  hydroxide,  and  boiled  in  a  test-tube.     The 
evolution  of  alkaline  vapours  can  be  detected  by  means  of 
a  strip  of  moistened,  red  litmus-paper. 

The  reaction-mixture  contains  potassium  propionate.  On 
acidifying  with  dilute  sulphuric  acid  and  distilling,  propionic 
acid  passes  over,  the  distillate  turning  blue  litmus  red. 


IX.    SATURATED  ACIDS,   CnH2nO2;   AND  ESTERS. 
(79-88;  91-95.) 

i.  Formic  Acid. — A  mixture  of  10  g.  of  glycerol  and  10  g.  of 
crystallized  oxalic  acid  is  heated  in  a  fractionating-flask  con- 
nected with  a  condenser.  Carbon  dioxide  is  evolved,  as  can  be 
demonstrated  by  holding  a  test-tube  containing  lime-water  at 
the  outlet  of  the  condenser  so  that  the  gas  enters  the  tube. 
After  an  energetic  evolution  of  gas  has  continued  for  some  time, 


16     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY      [ix. 

5  g.  of  crystallized  oxalic  acid  are  added,  and  the  heating 
renewed.     Formic  acid  distils  (153). 

2.  Decomposition  of  Mercuric  Formate.  —  A  portion  of  the 
distillate  of  i  is  agitated  with  a  small  quantity  of  finely-divided 
mercuric  oxide,  prepared  by  triturating  the  powder  in  a  mortar 
with  a  little  water.  The  resulting  solution  of  mercuric  for- 
mate is  filtered  from  the  excess  of  mercuric  oxide,  and  heated. 
At  first,  carbon  dioxide  is  evolved,  and  white  mercurous  for- 
mate precipitated.  On  further  heating,  the  mercurous  salt  is 
decomposed  with  evolution  of  carbon  dioxide,  and  precipita- 
tion of  metallic  mercury: 


TT 

HgOOCH  +  C02  +  HCOOH; 

Mercurous 


Mercuric  formate  formate 

Hg|OOCH+H|COQ|Hg  =  2Hg  +  C02  +  HCOOH. 

Mercurous  formate 

The  liquid  now  contains  free  formic  acid,  and,  therefore, 
turns  blue  litmus  red.  It  is  filtered,  and  the  filtrate  is  neu- 
tralized exactly  with  sodium  or  ammonium  hydroxide;  on 
addition  of  silver-nitrate  solution,  silver  formate  is  precipitated. 
When  this  is  heated,  it  decomposes  with  evolution  of  carbon 
dioxide,  liberating  half  the  formic  acid  and  precipitating  metallic 
silver,  analogously  to  the  mercury  salt.  The  reaction  of  the 
liquid,  therefore,  again  becomes  acid. 

3.  Action  of  Concentrated  Sulphuric  Acid  on  Formic  Acid.  — 
Another  portion  of  the  distillate  of  i  is  placed  in  a  sir  all  flask, 
and  kept  cool  during  the  slow  addition  of  twice  its  volume  of 
sulphuric  acid.  The  flask  is  closed  with  a  cork  and  delivery- 
tube,  the  end  of  the  latter  dipping  under  water  in  a  pneumatic 
trough.  On  the  application  of  heat,  a  gas  is  evolved.  It  is 
collected  in  a  cylinder,  and,  on  ignition,  burns  with  the  blue 
flame  characteristic  of  carbon  monoxide.  Agitation  of  the 
contents  of  the  cylinder  with  lime-water  produces  turbidity, 
proving  the  formation  of  carbon  dioxide  by  the  combustion. 


rx.]  SATURATED  ACIDS,  CnH2nO2;  AND  ESTERS  17 

4.  Oxidation  of  Formic  Acid  by  Potassium  Permanganate. — 

The  remainder  of  the  formic  acid  obtained  in  i  is  heated  with  a 
small  quantity  of  potassium  permanganate  and  dilute  sulphuric 
acid  in  the  apparatus  employed  in  3,  the  end  of  the  delivery- 
tube  being  immersed  in  lime-water  contained  in  a  test-tube. 
The  permanganate  solution  is  decolorized,  and  the  carbon 
dioxide  produced  by  the  oxidation  of  the  formic  acid  renders 
the  lime-water  turbid. 

5.  Cacodyl-Test  for   Acetic   Acid. — On  distilling  sour    beer 
(200  c.c.),  an  acid  distillate  is  obtained  with  an  odour  of  acetic 
acid.     The  distillate  is  nearly  neutralized  with  a  few  drops  of 
sodium-hydroxide    solution,    a    slightly    acid    reaction    being 
maintained.     It  is  then  evaporated,  the  last  traces  of  water 
being  removed  by  heating  over  a  free  flame.     A  portion  of 
the  anhydrous  sodium  acetate  thus  obtained  is  mixed  with 
arsenious   oxide,   and   the  mixture  heated  gently  in   a  test- 
tube.      The  excessively  disagreeable  odour  of  cacodyl  oxide, 
(CH3)2As — 0 — As(CHs)2,  is  soon  perceived  (73).     This  sub- 
stance being  extremely  poisonouSj  great  care  must  be  exercised 
in  carrying  out  the  experiment,  and  the  heating  should  be  dis- 
continued as  soon  as  the  odour  has  been  detected. 

6.  Stability  of  Acetic  Acid  towards  Oxidizing  Agents. — Small 
quantities    of    dilute    potassium-permanganate    solution  and 
dilute  sulphuric   acid   are   added  to   5  drops  of  acetic  acid. 
Unlike  formic  acid,  the  acetic  acid  does  not  decolorize  the 
permanganate  solution. 

7.  Silver  Acetate. — 1  g.  of  sodium  acetate  is  dissolved  in 
10  c.c.  of  water,  and  a  solution  of  silver  nitrate  added.     The 
precipitate  of  silver  acetate,  which  is  only  slightly  soluble  in 
water  at  the  ordinary  temperature,  is  collected  on  a  filter,  and 
sufficient  to  saturate  the  aqueous  solution  at  the  boiling-point 
transferred  to  a  beaker  containing  50  c.c.  of  boiling,  distilled 
water.     On  cooling,  the  salt  crystallizes  in  long,  silky  needles. 
These  are  filtered  off,  spread  on  a  porous  plate  to  remove  as 
much  of  the  mother-liquor  as  possible,  and  dried  in  a  dish  on 


18     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY      [ix 

the  water-bath.  On  carefully  heating  the  salt  in  a  porce- 
lain crucible,  it  decomposes,  leaving  a  residue  of  metallic 
silver. 

8.  Test  fdr  Acetic  Acid. — A  few  drops  of  ferric  chloride  are 
added  to  a  dilute  solution  of  sodium  acetate.     Owing  to  the 
formation  of  a  complex  aceto-ferric  acetate,  the  liquid  turns 
blood-red.    On  boiling  this  solution,  a  reddish-brown,  flocculent 
precipitate  of  basic  acetate  of  iron  is  formed.     If  allowed  to 
stand  for  a  short  time,  this  sinks  to  the  bottom  of  the  test- 
tube,  leaving  the  supernatant  liquid  colourless. 

9.  Oxidation  of  Ethyl  Alcohol  to  Acetic  Acid. — A  mixture  of 
6  g.  of  potassium  dichromate  and  10  g.  of  concentrated  sulphuric 
acid  is   introduced  into   a   100-c.c.   distilling-flask   connected 
with  a  condenser,  and  a  solution  of  2  c.c.  of  alcohol  in  10  c.c. 
of  water  added  drop  by  drop  from  a  tap-funnel.     On  heating, 
acetic  acid  distils,  and  can  be  recognized  by  its  odour,  or,  after 
careful    neutralization  with  sodium  carbonate,  by  the  ferric- 
chloride  test  (8). 

10.  Action  of  Caustic  Alkalis  on  Sodium  Acetate. — One  part 
by  weight  of  sodium  acetate,  which  has  been  fused  and  finely 
powdered,  is   thoroughly  mixed  with  four  parts  by  weight  of 
soda-lime.     The  mixture  is  heated  in  a  hard-glass  retort  of 
100  c.c.  capacity,  fitted  with  a  delivery-tube  for  collecting  the 
gas  in  cylinders  over  water.     The  gas  is  collected  in  a  thick- 
walled  cylinder  and  ignited  (IV.,  i). 

Methane  thus  prepared  always  contains  some  hydrogen, 
and  to  obtain  a  product  of  maximum  purity,  it  is  best  to 
keep  the  temperature  as  low  as  possible. 

11.  Saponification    of    Butter. — About    5   g.   of    butter  are 
saponified  by  boiling  in  a   porcelain   dish  with   20  c.c.  of   a 
solution  of  1  part  of  sodium  hydroxide  in  2  parts  of  water, 
the  mixture  being  constantly  stirred.     After  a  few  minutes, 
it  begins  to  foam.     The  heating    is    continued    for   twenty 
minutes,  and  the  contents  of  the  dish  allowed  to  cool.     The 
liquid    separates    into    two    layers — the    lower    an    aqueous 


ix.]  SATURATED  ACIDS,  CnH2nO2;  AND  ESTERS  19 

solution  of  glycerol  and  sodium  hydroxide,  and  the  upper 
the  fused  sodium  salts  of  the  fatty  acids,  which  are  insoluble 
in  concentrated  sodium-hydroxide  solution.  When  cold,  the 
upper  layer  is  semi-solid.  It  is  separated  from  the  aqueous 
solution,  and  dissolved  in  water  to  free  it  from  unsaponified 
fat.  This  can  be  almost  completely  removed  by  filtration 
through  a  moistened  filter-paper. 

12.  Calcium  and  Lead  Salts  of  the  Higher  Fatty  Acids. — A 
part  of  the  soap  solution  obtained  by  the  method  described 
in  ii  is  neutralized  with  dilute  acetic  acid,  and  calcium  chloride 
and  lead  acetate  respectively  (idded  to  separate  portions.     Pre- 
cipitates of  the  calcium  and  lead  salts  of  the  higher  fatty  acids 
are  formed. 

13.  Volatile  Fatty  Acids. — The  rest  of  the  soap  solution  is 
poured  into  a  100-c.c.  distilling-flask  connected  with  a  condenser, 
and  excess  of  dilute  sulphuric  acid  added.     On  heating,  water 
and  the  volatile  fatty  acids  of  the  butter  distil,  chief  of  the  latter 
being  ?i-butyric  acid.      They  can  be  detected  by  their  odour 
and  acid  reaction. 

14.  Higher  Fatty  Acids.— After  the  distillation  of  the  vola- 
tile fatty  acids,  the  residue  in  the  flask  consists  of  the  solid 
higher  fatty  acids.     It  is  transferred  to  a  porcelain  dish,  allowed 
to   cool,   and   the   solid  layer  of  fatty   acids  triturated  with 
water  several  times  to  remove  adhering  sulphuric  acid.     To 
prove  that  the  mixture  has  an  acid  reaction,  it  is  dissolved  in 
alcohol,  and  the  solution  added  drop  by  drop  to  a  very  dilute 
solution  of  sodium  hydroxide  coloured  red  by  a  drop  of  phenol- 
phthale'in.     The   colour   disappears,    and   the   acids   dissolve, 
proving  that  the  alkali  has  been  neutralized. 

15.  Soap. — A  few  drops  of  an  alcoholic  solution  of  phenol- 
phthalein  are  added  to  a  concentrated,  neutral  soap  solution. 
On  dilution  with  a  large  excess  of  water,  the  colourless  liquid 
becomes  red,  owing  to  the  liberation  of  free  alkali  by  the 
hydrolytic  dissociation  of  the  salts  of  the  fatty  acids. 

A  solution  of  calcium  sulphate  is  added  to  one  of  soap, 


20     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY      [ix. 

whereupon  the  calcium  salts  of  the  higher  fatty  acids  are  pre- 
cipitated. 

16.  Emulsifying  Action  of  Soap. — About  2  g.  of   soap   are 
dissolved  in  sufficient  water  to  render  the  solution  alkaline, 
a  few  drops  of  oil  are   added,   and  the  solution  vigorously 
agitated.     An  emulsion  is  produced. 

17.  Cleansing    Action    of    Soap. — A   mixture   of   soot   and 
water  is  decanted  into  a  filter.     The  filter-paper  is  then  removed 
from  the  funnel,  refolded  with  the  black  surface  outward,  and 
replaced    in    the    funnel.     Water    poured    into    the    reversed 
filter  remains  clear  during  percolation;  but  filtration  of  a  soap- 
solution  renders  it  black,  and  cleanses  the  paper  completely. 

1 8.  Ethyl   Acetate. — Dry  hydrochloric-acid    gas    is  passed 
into  a  mixture  of  10  c.c.  of  glacial  acetic  acid  and  15  c.c.  of  90 
per  cent  alcohol.     The  gas  can  be  prepared  by  gently  heating 
dried  common  salt  with  concentrated  sulphuric  acid  in  a  flask, 
or  can  be  obtained  from  a  KIPP  generator  charged  with  lump 
ammonium   chloride   and   concentrated   sulphuric  acid.     The 
mixture  is  heated  for  an  hour  under  a  reflux-condenser,  and 
then  poured   into   brine.     Drops   of   ethyl   acetate   separate, 
a  liquid  characterized  by  its  pleasant  and  refreshing  odour. 

19.  Velocity    of    Saponification    of    Ethyl    Acetate. — A  small 
quantity   of   ethyl    acetate   is   dissolved   in   water,    and   like 
volumes  of  the  solution  transferred  to  two  test-tubes  fitted 
with   corks.     One  portion  is   agitated  with  a  few  drops  of 
potassium  or.  sodium  hydroxide,   and  the  other  with  a  like 
volume  of  dilute  sulphuric  acid.     Since  the  saponification  is 
effected  much  more  rapidly  by  the  caustic  alkali  than  by  the 
acid,  the  odour  of  the  ester  vanishes  from  the  first  tube  much 
sooner  than  from  the  second. 

20.  Solubility    of    Ethyl    Acetate    in   Water.— An  excess   of 
ethyl  acetate  is  vigorously  agitated  with  25  c.c.  of  water  at 
the  ordinary  temperature  till  saturation  is  complete,  and  the 
aqueous   solution   is   separated   from   the   undissolved   ester. 
When  warmed,  the  solution  becomes  turbid  from  the  separa- 


x.]  ALDEHYDES  AND  KETONES  21 

tion  of  ethyl  acetate,  which  is  more  soluble  in  cold  than  in  hot 
water. 


X.    ALDEHYDES  AND  KETONES. 
(98-111.) 

ALDEHYDES   (98-109). 

1.  Acetaldehyde. — A  mixture   of   60  g.  of  water,  20  g.  of 
concentrated  sulphuric  acid,   and   15  g.  of  ninety  per  cent, 
alcohol  is  added  to  13  g.  of  potassium  dichromate  contained 
in  a  200-c.c.  fractionating-flask  connected  with  a  condenser. 
Sometimes    the    oxidation    begins    spontaneously;    should    it 
not,  however,  the  flask  is  gently  heated  on  a  sand-bath,  with 
a  rapid  current  of  cold  water  flowing  through  the  condenser. 
A  mixture  of  water,  alcohol,  acetaldehyde,  and  acetal  distils, 
and    can    be    used    in    carrying    out    the    aldehyde-reactions 
described  in  2,  3,  and  4. 

2.  Silver-mirror  Test. — A  small  portion  of  the  distillate  is 
diluted  with  water  in  a  clean  test-tube,  and  a  few  drops  of  an 
ammoniacal    silver    solution    added.     This    is    prepared    by 
adding  a  small  excess  of  a  solution  of  sodium  hydroxide  to 
one  of  silver  nitrate,  and  then  ammonium  hydroxide  drop  by 
drop  in  exactly  sufficient  quantity  to  redissolve  the  precipitate. 
After  being  shaken,  the  test-tube  is  immersed  in  water  heated 
almost  to  its  boiling-point.     If  the  tube  is  thoroughly  clean, 
the  reduced  silver  is  deposited  on  its  sides  as  a  mirror;  if  not, 
a  black  precipitate  of  the  metal  is  obtained. 

3.  Aldehyde-resin. — Potassium  hydroxide  is  added  to  another 
portion  of  the  distillate,  and  the  mixture  warmed.     A  yellow 
coloration  is  produced  at  once,   and,   on  further  heating,   a 
precipitate  of  aldehyde-resin  is  formed. 

4.  SCHIFF'S    Reaction. — Another  portion  of  the  distillate 
is  added  to  a  solution  of  magenta  decolorized  with  sulphurous 
acid — SCHIFF'S  reagent.     The  red  colour  of  the  dye  is  restored. 


22     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY      [x. 

5.  Production  of  Formaldehyde. — A    red-hot    copper    spiral 
is  placed  in  a  test-tube  containing  1  c.c.  of  methyl  alcohol, 
and  a  cork  is  loosely  inserted  in  the  mouth  of  the  tube.     When 
cold,  the  spiral  is  removed,  and  the  presence  of  formaldehyde 
detected  by  the  reduction  of  FEHLING'S  solution  (XVI.,  6). 

6.  Action   of  Formalin    on    Proteins. — The  yolk  of  an  egg 
is  carefully  placed  in  formalin.     After  the  lapse  of  some  time, 
it  will  be  found  to  have  acquired  the  consistency  of  an  india- 
rubber  ball. 

7.  Non-re sinification    of    Formaldehyde. — A    few    drops    of 
formalin   are  diluted  with  water,  and   a  solution  of   sodium 
hydroxide  added.     Heating  the  liquid  produces  no  resinification. 

KETONES  (98-103,  110  and  111). 

8.  Acetone. — About   50   g.   of   dried   calcium   acetate   are 
heated  to  a  high  temperature  in  a  retort  connected  with  a 
condenser.     Acetone  is  the  principal  constituent  of  the  dis- 
tillate, to  which  the  by-products  present  impart  an  empyreuma- 
tic  odour.     On  addition  of  water,  most  of  the  liquid  dissolves; 
the   insoluble   tar-like   products   are   separated   by   filtration 
through  a  moistened  filter-paper. 

9.  Test    for  Acetone. — The  filtrate  obtained  in  8  is  added 
to  a  solution  of  mercuric  nitrate  made  strongly  alkaline  by 
addition  of  alcoholic  potash.     On  agitating  the  mixture,  the 
acetone  dissolves  a  part  of  the  mercuric  oxide  suspended  in 
the  liquid.     By  repeated  filtration,  a  clear  filtrate  is  obtained. 
On   addition   of   ammonium   sulphide   to   this,   a  precipitate 
of  mercuric  sulphide  is  formed,  proving  the  presence  of  mer- 
cury in  the  solution. 

10.  Addition-product  of  Acetone  and  Sodium  Hydrogen  Sul- 
phite.— 5  c.c.  of  acetone  are  agitated  with  a  like  volume  of  a 
very  concentrated  solution  of  sodium  hydrogen  sulphite;  a 
crystalline  addition-product  is  precipitated,  being  almost 
insoluble  in  the  concentrated  sulphite  solution.  On  addi- 
tion of  water,  it  dissolves. 


xi.]         UNSATURATED  HYDROCARBONS         23 

11.  Separation  of  Acetone  from  Aqueous  Solution. — 5  c.c.  of 
acetone  are  added  to  a  like  volume  of  water,  with  which  the 
ketone  is  miscible  in  all  proportions.     On  addition  of  solid 
potassium  hydroxide  to  the  mixture  till  saturation  is  complete, 
the  liquid  separates  into  two  layers,   the  upper   one   being 
chiefly  acetone,  and  the  lower  an  aqueous  solution  of  potassium 
hydroxide  containing  traces  of  acetone. 

12.  Oxidation  of  Acetone. — An  aqueous  solution  of  2  c.c.  of 
acetone  is  prepared,  and  a  dilute  solution  of  potassium  per- 
manganate added  till  the  pink  colour  of  the  liquid  persists. 
After  removal  of  the  manganese  dioxide  by  filtration,   the 
filtrate  is  acidified  with  dilute  sulphuric  acid  and  distilled^ 
After    careful    neutralization    with    sodium     carbonate,    the 
presence  of  acetic  acid  in  the  distillate  can  be  proved  by  the 
ferric-chloride  test  (IX.,  8). 

XI.    UNSATURATED   HYDROCARBONS. 

(112-127.) 
OLEFINES  (112-120). 

1.  Ethylene. — A  mixture  of  20  c.c.  of  alcohol  of  eighty  per 
cent,  strength  and  120  c.c.  of  concentrated  sulphuric  acid  is 
allowed  to  stand  for  some  time.     It  is  then  heated  in  a  large 
flask  on  a  sand-bath,  the  tendency  to  foam  being  checked  by 
the  addition  of  7  g.  of  anhydrous  aluminium  sulphate,  or  a 
quantity  of  sand.     The   ethylene   evolved   is   collected   over 
water  in  cylinders,  being  thereby  freed  from  most  of  the  car- 
bon dioxide  and  sulphur  dioxide  generated  along  with  it. 

2.  Luminosity   of    the   Ethylene    Flame. — One  of  the  cylin- 
ders is  turned  mouth  upwards,  and  its  contents  ignited;    the 
ethylene  burns  with  a  luminous  flame. 

3.  Action   of  Bromine    on    Ethylene. — A  small  quantity  of 
bromine-water  is  added  to  another  cylinder,   the  open  end 
closed  with  a  glass  plate,  and  the  contents  agitated.     The 


24     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY      [xi. 

red  colour  is  discharged,  and  oily  drops  of  ethylene  bromide, 
C2H4Br2,  collect  on  the  sides  of  the  cylinder,  the  character- 
istic odour  of  this  compound  also  becoming  perceptible. 

4.  VON  BAEYER'S  Test  for  the  Double  Bond. — The  gas  in  a 
third  cylinder  is  shaken  up  with  mixed  aqueous  solutions  of 
potassium  permanganate  and  sodium  carbonate.     The  violet 
colour  of  the  solution  is  discharged,  and  a  brown  precipitate 
of  hydrated  manganese  dioxide,  MnCb/ftH^O,  formed. 

5.  Explosive    Mixture    of   Ethylene    and    Oxygen. — A  thick- 
walled  cylinder  one-quarter  full  of  ethylene  is  filled  up  with 
oxygen,  the  contents  mixed  by  shaking,  and  a  light  applied. 
The  mixture  explodes  with  a  loud  report. 

6.  Unsaturated    Hydrocarbons  in  Coal-gas. — Two  cylinders 
are  filled  with  coal-gas  by  displacement  of  water.     By  the 
application  of  the  tests  described  in  3  and  4,  the  gas  can  be 
shown  to  contain  unsaturated  compounds. 

7.  Double    Linking   in   Amylene. — The  presence  of  a  double 
linking  in   amylene   can   be   demonstrated   by  the  reactions 
described  in  3  and  4. 

ACETYLENE  (126). 

8.  Preparation  of    Acetylene. — A  piece  of  calcium  carbide 
is  dropped  into  water  contained  in  a  100-c.c.  fractionating- 
flask  fitted  with  a  delivery-tube  dipping  under  water,  and  the 
neck  of  the  flask  quickly  closed  with  a  cork.     A  vigorous 
evolution  of  acetylene  ensues.     The  gas  is  collected  in  cylin- 
ders, and  submitted  to  the  tests  described  in  2,  3,  and  4. 

9.  Copper  Acetylene  and  Silver  Acetylene. — An  ammoniacal 
solution  of  cuprous  chloride  is  prepared  by  adding  ammonium 
hydroxide  to  a  mixture  of  cuprous  chloride  and  water  till  solu- 
tion is  complete.     On  addition  of  a  portion  of  this  liquid  to  a 
cylinder  containing  acetylene  a  red  precipitate  of  copper  acety- 
lene is  formed,  readily  soluble  in  hydrochloric  acid  with  evolu- 
tion of  acetylene. 

An  ammoniacal  silver  solution — prepared  by  adding  ammo- 


xii.]  MONOBASIC  UNSATURATED  ACIDS  25 

nium  hydroxide  carefully  to  a  solution  of  silver  nitrate  till  the 
precipitate  first  formed  has  just  redissolved — gives  with 
acetylene  a  white  precipitate  of  silver  acetylene. 


XII.    MONOBASIC  UNSATURATED  ACIDS. 
(134-138.) 

1.  Double   Bond   in  Almond  Oil. — 5  c.c.  of  almond  oil,  con- 
sisting principally  of  glyceryl  oleate,  are  diluted  with  10  c.c. 
of  ether  or  carbon  disulphide.     A  portion  of  the  solution  is 
agitated  with  bromine-water;    the  colour  is  discharged.     To 
another  portion  is  added  a  solution  of  potassium  permanganate 
and  sodium  carbonate;   a  brown  precipitate  of  hydrated  man- 
ganese dioxide  is  obtained. 

2.  Oleic  Acid   from  Almond   Oil. — 5  c.c.  of  almond  oil  are 
saponified  by  the  method  described  in    IX.,  n,  the  heating 
with  sodium  hydroxide  being  continued  for  not  less  than  an 
hour.     Periodically,  water  is  added  to  replace  that  lost  by 
evaporation.     The  resulting  sodium-soap  is  dissolved  in  water 
and  the  solution  acidified  with  dilute  sulphuric  acid.     The 
liberated  oleic  acid  forms  a  liquid  layer  on  the  surface  of  the 
aqueous  solution,  from  which  it  is  removed  by  the  aid  of  a 
separating-funnel.     The   tests   for   double   linkings   described 
in  XI.,  3  and  4,  are  carried  out  with  portions  of  this  acid. 

3.  Elaidic  Transformation. — Some  of  the  liquid  oleic  acid  is 
poured  into  2  or  3  c.c.  of  a  concentrated  solution  of  sodium 
nitrite,  a  small  quantity  of  dilute  sulphuric  acid  added,  and 
the   mixture   allowed   to   stand   for    some    time.     Owing   to 
its   transformation   into   elai'dic   acid,    the   liquid   oleic    acid 
gradually  becomes  solid. 

4.  Fusion  of  Oleic  Acid  with  Caustic  Alkali. — 5  g.  of  sodium 
hydroxide  are  heated  to  fusion  with  a  few  drops  of  water  in  an 
iron  crucible,  and  2  c.c.  of  olei'c  acid  added.     The  mixture  is 
stirred,  and  maintained  for  some  time  in  the  fused  state. 


26     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY    [xm. 

After  cooling,  it  is  dissolved  in  water,  and  excess  of  dilute 
sulphuric  acid  added.  On  distillation  from  a  fractionating- 
flask,  an  acid  distillate  is  obtained,  containing  acetic  acid. 

5.  Lead  Oleate. — 5  c.c.  of  almond  oil,  25  c.c.  of  water, 
and  10  g.  of  lead  monoxide  are  boiled  in  a  porcelain  dish, 
with  constant  stirring,  until  the  red  colour  of  the  lead 
oxide  has  disappeared.  The  operation  requires  at  least  an  hour. 
Water  is  added  periodically  to  replace  that  lost  by  evapora- 
tion. After  cooling,  the  water  is  poured  off,  and  the  plaster- 
like  lead  oleate  (so-called  "  lead-plaster  ")  formed  is  triturated 
thoroughly  with  ether  by  the  aid  of  a  pestle.  After  filtering, 
and  distilling  the  ether,  the  lea-d  oleate  is  left  in  the  semi-solid 
state.  Addition  of  hydrogen-sulphide  solution  proves  the 
presence  of  lead,  a  black  precipitate  of  lead  sulphide  being 
produced. 


XIII.    CHLOROFORM  AND  IODOFORM. 

(144-146.) 

1.  Preparation    of    Chloroform. — 25   g.   of  fresh  bleaching- 
powder,  10  c.c.  of  alcohol  of  eighty-five  per  cent,  strength,  and 
10  c.c.  of  water  are  heated  gently  in  a  litre  flask  on  a  sand- 
bath  till  the  reaction  begins;    the  flame  is  then  removed. 
There  is  much  foaming,  and  water  and  chloroform  distil,  the 
latter  constituting  the  lower  layer  of  the  distillate. 

2.  Formation  of  Chloroform  from  Trichloroacetic  Acid. — An 
aqueous  solution  of  1  g.  of  trichloroacetic  acid  is  boiled  in  a 
fractionating-flask.     Carbon   dioxide  is  evolved,  and  can  be 
identified  by  its  action  on   lime-water.     When  the  mixture 
has  cooled,  the  presence  of  chloroform  in  the  flask  can  be 
detected  by  the  odour. 

3.  Action   of  Potassium  Hydroxide   on   Chloroform. — A  few 
drops  of  chloroform  are  heated  in  a  test-tube  with  a  small 
quantity  of  dilute  potassium  hydroxide,  potassium  chloride 


xiv.]  GLYCEROL  27 

and  potassium  formate  being  produced.  The  mixture  is 
neutralized  so  as  to  maintain  a  slightly  alkaline  reaction, 
and  heated  with  a  solution  of  mercuric  chloride.  Reduction 
to  mercurous  chloride,  and  then  to  metallic  mercury,  proves 
the  presence  of  dissolved  formate  (IX.,  2). 

4.  Conversion  of  Chloroform  into  Potassium  Cyanide. — 1  c.c. 
of  chloroform  is  heated  in  a  test-tube  for  a  short  time  with 
5  c.c.  of  concentrated  alcoholic  ammonia  and  1  c.c.  of  con- 
centrated alcoholic   potash.     The   liquid  is  transferred  to   a 
porcelain  dish,  and  evaporated  to  dryness  on  a  water-bath. 
The  presence  of  potassium  cyanide  in  the  residue  is  detected 
by  the  method  employed  in  LASSAIGNE'S  test  for  nitrogen 
(I.,  3  a). 

5.  Chloroform   and    Silver    Nitrate. — 1  c.c.  of  chloroform  is 
agitated  three  or  four  times  with  water  in  a  test-tube,  using 
about  10  c.c.  for  each  operation;    traces  of  hydrochloric  acid, 
if  present,  are  thus  eliminated.     More  water  and  2  or  3  drops 
of  silver-nitrate  solution  are  then  added.     A  precipitate  of 
silver  chloride  is  not  formed. 

6.  lodoform-Test  for  Alcohol. — To  1  c.c.  of  alcohol  in  a  test- 
tube  are  added  10  c.c.  of  a  moderately  concentrated  solution  of 
iodine  in  potassium-iodide  solution,  and  potassium  hydroxide 
drop  by  drop  till  the  brown  colour  of  the  iodine  is  discharged. 
A  yellow,  crystalline  precipitate  of  iodoform  is  obtained,  dis- 
tinguished by  its  characteristic  odour.     Under  the  microscope, 
the  crystals  are  seen  to  be  six-sided,  dichroic  (reddish-green) 
plates. 


XIV.    GLYCEROL. 

(151-155.) 

i.  Preparation  of  Allyl  Alcohol. — 10  c.c.  of  glycerol  and 
12  g.  of  crystallized  oxalic  acid  are  heated  in  a  retort  connected 
with  a  condenser.  At  first,  formic  acid  distils  (IX.,  i),  and 


28     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY      [xv. 

soon  oily  streaks  of  allyl  alcohol  are  seen  on  the  sides  of  the 
retort.  The  distillation  is  continued  with  another  receiver, 
this  alcohol  passing  over.  It  is  characterized  by  an  irritating 
odour.  On  heating  it  with  chromic-acid  solution,  the  powerful, 
penetrating  odour  of  acraldehyde  is  perceived. 

2.  Test  for   Glycerol. — 1  c.c.  of  glycerol  is  heated  in  a  dish 
with  5  g.  of  sodium  pyrosulphate,   Na2S2Or;    the  odour  of 
acraldehyde  is  soon  manifested. 

3.  Action  of  Alkalis  on  Copper  Salts  in  Presence  of  Glycerol. — 
5  c.c.  of  dilute  copper-sulphate  solution  are  added  to  1  c.c.  of 
glycerol.     On  addition  of  potassium  hydroxide  to  this  mixture, 
copper  hydroxide,  Cu(OH)2,  is  not  precipitated.     Instead,  a 
soluble  copper  alkoxide  of  glycerol  is  formed,  imparting  a  deep- 
blue  colour  to.  the  solution. 


XV.    SATURATED  DIBASIC  ACIDS. 

(161-168.) 
OXALIC  ACID  (162). 

i.  Preparation  of  Oxalic  Acid  from  Wood. — A  concentrated 
solution  of  potassium  (not  sodium)  hydroxide  is  added  to  10 
g.  of  sawdust,  so  as  to  form  a  thick  paste,  and  the  mixture 
heated  on  a  shallow  iron  dish,  and  constantly  stirred.  The 
first  product  is  potassium  formate;  on  further  heating,  it  loses 
hydrogen,  yielding  potassium  oxalate  (2).  The  heating  is 
continued  for  a  few  minutes  after  rapid  evolution  of  hydrogen 
from  the  mass  in  large  bubbles  which  burn  on  ignition  has 
begun,  and  then  stopped,  to  prevent  decomposition  of  the 
oxalate  formed.  When  cold,  the  reaction-mixture  is  lixiviated 
with  water,  filtered  through  a  folded  filter,  and  acidified  with 
dilute  acetic  acid.  On  addition  of  calcium-chloride  solution, 
calcium  oxalate  is  precipitated,  insoluble  in  acetic  acid,  but 
soluble  in  cold,  and  more  readily  in  warm,  hydrochloric  acid. 


xv.]  SATURATED  DIBASIC  ACIDS  29 

2.  Conversion    of   Formates   into    Oxalates. — 2    g.   of  dried 
sodium  formate  are  heated  to  a  high  temperature  in   a   test- 
tube.     Hydrogen  is  evolved,  and  can  be  ignited  after  all  the 
air  has  been  expelled  from  the  tube.     The  white  residue  is 
proved  to  be  sodium  oxalate  by  dissolving  it  in  water,  and 
adding  a  solution  of  calcium  chloride;   a  precipitate  of  calcium 
oxalate,  insoluble  in  dilute  acetic  acid,  is  formed. 

3.  Calcium,  Lead,  and  Copper  Oxalates. — These  oxalates  are 
prepared  by  adding  solutions  of  calcium  chloride,  lead  acetate, 
and  copper  sulphate  respectively  to  a  ten  per  cent,  solution  of 
ammonium  oxalate  till  precipitation  is  complete,  50  c.c.  of  the 
ammonium-oxalate  solution  being  used  for  each  experiment. 
The  salts   are   collected  on  filters,   washed  thoroughly  with 
water,  and  spread  on  porous  plates  to  dry.      The  last  traces 
of  moisture  are  eliminated  by  heating  them  in  porcelain  dishes 
on  the  water-bath. 

4.  Decomposition  of  Calcium  Oxalate  by  Heat. — 3  g.  of  cal- 
cium oxalate  are  heated  in  a  hard-glass  test-tube  fitted  with  a 
delivery-tube.     When  the  temperature  has  risen  above  200°, 
water  of  crystallization  condenses  on  the  sides  of  the  tube; 
on  further  heating,  carbon  monoxide  is  evolved.     The  gas  is 
collected  in  a  cylinder,  and  its  identity  established  by  the 
method  of  IX.,  3.     The  residue  in  the  tube  is  calcium  carbonate; 
when  cold,  it  is  treated  with  hydrochloric  acid,  causing  a  vigor- 
ous evolution  of  gas.      This  is  proved  to  be  carbon  dioxide  by 
its  action  on  lime-water. 

5.  Decomposition  of  Lead  and  Copper  Oxalates  by  Heat. — 
The  experiment  described  in  4  is  carried  out  in  separate  tubes 
with  3  g.  of  lead  oxalate  and  a  like  weight  of  copper  oxalate. 
Both   evolve   carbon   dioxide,    as   proved   by  the   lime-water 
test;  lead  and  copper  remain  in  the  tubes. 

6.  Action  of  Concentrated   Sulphuric  Acid   on  Oxalic  Acid. — 
A  100-c.c.  distilling-flask  is  connected  with  a  wash-bottle  con- 
taining a  mixture  of  potassium-hydroxide  solution  and  lime- 
water  and  fitted  with  a  delivery-tube.     In  the  flask  are  placed 


30     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY     [xv. 

5  g.  of  oxalic  acid  and  10  c.c.  of  concentrated  sulphuric  acid. 
The  flask  is  closed  with  a  cork,  and  heated  gently.  Gas  is 
evolved;  partly  carbon  dioxide,  which  renders  turbid  the 
lime-water  in  the  wash-bottle;  and  partly  carbon  monoxide, 
which  is  not  absorbed.  The  latter  is  collected  in  cylinders, 
and  identified  by  the  method  of  IX.,  3. 

7.  Complex  Oxalates. — a)     A    solution  of  ammonium  oxa- 
late  is  added  carefully  to  2  c.c.  of  a  five  per  cent,  solution  of 
copper    sulphate.     Copper    oxalate   is   precipitated,    and,    on 
further  addition  of  the  ammonium  salt,  redissolves,  forming 
copper  ammonium  oxalate. 

6)  2  g.  of  "  salt  of  sorrel,"  KHC2O4,H2C204,2H20,  are 
dissolved  in  10  c.c.  of  water.  To  this  solution  is  added 
freshly-precipitated  ferric  hydroxide,  obtained  by  adding 
ammonium  hydroxide  to  a  boiling,  dilute  solution  of  ferric 
chloride,  allowing  the  precipitate  to  subside,  and  washing  it 
by  decantation.  On  warming,  the  ferric  hydroxide  dissolves, 
yielding  potassium  ferric  oxalate,  KsFefX^O^s.  The  green 
colour  of  this  solution  should  be  noted;  it  points  to  the  absence 
of  Fe-ions,  and  to  the  presence  of  complex  [Fe(C2O4)3]///-anions. 

c)  A  like  solution  of  "  salt  of  sorrel  "  is  added  to  5  c.c.  of  a 
ten  per  cent,  solution  of  ferrous  sulphate  until  the  precipitate 
first  formed  redissolves.  This  solution  reduces  platinum 
chloride.  Its  yellow  colour  is  due  to  the  complex  [FefX^O^]"- 
anion. 

8.  Action   of   Light   on   EDER'S    Solution. — A  mixture  of  2 
volumes  of  a  4  per  cent,  solution  of  ammonium  oxalate  and  1 
volume  of  a  5  per  cent,  solution  of  mercuric  chloride  (EDER'S 
solution)  is  divided  into  two  equal  parts,  and  a  few  drops  of 
eosin  solution  are  added  to  one  of  them.     After  exposure  to 
light  for  several  hours,   both  of  the  liquid  samples   contain 
a  precipitate  of  mercurous  chloride,  the  amount  of  this  salt 
deposited  in  the  solution  containing  the  sensitizer  eosin  being 
much  larger  than  in  the  other  solution. 

9.  Dimethyl  Oxalate. — Oxalic  acid  is  dried  at  100°,  and  3  g. 


xv.]  SATURATED  DIBASIC  ACIDS  31 

of  the  dry  acid  are  dissolved  in  10  c.c.  of  boiling  methyl  alcohol. 
On  cooling,  dimethyl  oxalate  crystallizes  out.  Some  of  the 
ester  is  dried  by  pressure  between  sheets  of  filter-paper,  and  its 
melting-point  taken.  M.  P.  54°. 

10.  Diethyl  Oxalate. — A  mixture  of  7  g.  of  anhydrous  oxalic 
acid  and  10  c.c.  of  absolute  alcohol  is  heated  slowly  in  a  50-c.c. 
fractionating-flask  connected  with  a  condenser  till  the  temper- 
ature rises  to  110°.     The  distillate  is  then  returned  to  the  flask, 
and  the  heating  continued  till  the  thermometer  reaches  180°. 
The  fraction  distilling  between  this  temperature  and  190°  is 
collected  separately,  and  is  principally  diethyl  oxalate. 

11.  Oxamide. — The  esters  obtained  in    experiments  9  and 
10  are  dissolved  separately  in  alcohol,  and  ammonium  hydr- 
oxide   added  to  each    solution.     From    both  a  precipitate  of 
oxamide  is  obtained,  insoluble  in  water,  alcohol,  and  ether. 

SUCCINIC  ACID  (166). 

12.  Barium  Succinate. — Ammonium  hydroxide  is  added  to 
10  c.c.  of  a  cold,  saturated  solution  of  succinic  acid  till  neutrali- 
zation is  complete.     On  addition  of  barium  chloride,  a  white, 
crystalline   precipitate   of   barium   succinate   is   formed,    the 
precipitation  being  facilitated  by  addition  of  alcohol. 

13.  Basic  Ferric  Succinate. — 10  c.c.  of  a  solution  of  succinic 
acid  are  carefully  neutralized,  and  ferric  chloride  added.     A 
brown,  gelatinous  precipitate  of  basic  ferric  succinate  is  formed. 

14.  Succinimide. — A  solution  of  10  g.  of    succinic  acid  in 
ammonium  hydroxide  is  evaporated  in  a  porcelain  dish  on  a 
sand-bath,  and  heated  till  the  temperature  of  the  fused  mass  is 
about  200°.     The  residue  is  transferred  to  a  small  fractionating- 
flask,  and  distilled  as  rapidly  as  possible.     The  distillate  is 
succinimide,  M.  P.  125°.     It  can  be  crystallized  from  alcohol. 


32     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY    [xvi. 

XVI.     HYDROXY-ACIDS. 

(179-197.) 
LACTIC  ACID  (182). 

1.  Decomposition  of  Lactic  Acid  by  Dilute  Sulphuric  Acid.— 
5  c.c.  of  lactic  acid  are  heated  with  a  mixture  of  5  c.c.  of  con- 
centrated sulphuric  acid  and  10  c.c.  of  water  in  a  retort  con- 
nected with  a  condenser.     The  distillate  contains  acetaldehyde 
and  formic  acid.     They  can  be  identified  by  the  silver-mirror 
test  (X.,  2),  and  the  mercuric-oxide  test  (IX.,  2),  respectively. 

2.  Decomposition  of  Lactic  Acid  by  Concentrated  Sulphuric 
Acid. — A  mixture  of  5  c.c.  of  lactic  acid  and  a  like  volume  of 
concentrated  sulphuric  acid  is  heated  in  a  retort  fitted  with  a 
delivery-tube.     The  gas  evolved  by  the  decomposition  of  the 
formic  acid  first  produced  can  be  proved  to  be  carbon  monoxide 
by  the  method  described  in  IX.,  3. 

3.  Oxidation    of    Lactic    Acid. — Dilute    sulphuric    acid    is 
added  to  a  solution  of  0*5  g.  of  lactic  acid,  and  the  mixture 
gently  heated  with  a  2  per  cent,  solution  of  potassium  perman- 
ganate.    The  odour  of  acetaldehyde  soon  becomes  perceptible. 

TARTARIC   ACID    (188-196). 

4.  Potassium     Tartrates. — Potassium    hydroxide   is    added 
drop  by  drop  to  5  c.c.  of  a  twenty  per  cent,  solution  of  tar- 
taric  acid.     A  precipitate  of  potassium  hydrogen  tartrate  is 
first  formed,  and,  on  further  addition  of  potassium  hydroxide, 
redissolves,  with  production  of  the  neutral  tartrate. 

5.  Iron    Ammonium    Tartrate. — A  solution  of  9  g.  of  ferrous 
sulphate  is  added  to  15  c.c.  of  a  solution  of  1  part  of  tartaric 
acid  in  2  parts  of  water;  excess  of  ammonium  hydroxide  pro- 
duces no  precipitate  with   this  mixture.     When  agitated  in 
presence  of  air,  this  liquid  absorbs  oxygen,  becoming  light- 
green,  then  dark-green,  and  finally  brown.     The  absorption 
of  oxygen  can  be  demonstrated  by  carrying  out  the  process  in  a  * 
flask  closed  with  an  air-tight  cork;   on  immersion  of  the  neck 
in  water  and  removal  of  the  cork,  the  water  rises  in  the  flask. 


xvi.]  HYDROXY-ACIDS  33 

After  replacement  of  the  cork,  the  flask  is  withdrawn  from 
the  water,  and  an  ignited  wood-splint  introduced  into  the 
residual  gas;  the  flame  is  at  once  extinguished. 

6.  FEHLING'S  Solution. — A  solution  of  copper  sulphate  is 
added  to  one  of  tartaric  acid,  and  then  potassium  hydroxide 
in  excess.     The  dark-blue  liquid  formed  is  known  as  FEHLING'S 
solution. 

7.  Action  of  Heat  on  Tartaric  Acid. — When  heated  in  a  test- 
tube,  tartaric  acid  becomes  brown,  and  acquires  a  caramel- 
like  odour.     When   heated   on  platinum-foil  or  nickel-foil,  it 
chars. 

8.  Microchemical  Test  for  Tartaric  Acid  and  Racemic  Acid. — 
Calcium  chloride  is  added  to  a  solution  of  tartaric  acid  satu- 
rated with    ammonia.     The  calcium  tartrate  precipitated    is 
only  slightly  soluble  in  dilute  acetic  acid. 

The  experiment  should  be  repeated  with  racemic  acid,  and  the 
crystals  of  the  two  calcium  salts  compared  under  the  microscope. 

9.  Relative  Solubility  of  Calcium  Tartrate  and  Calcium  Race- 
mate. — A  solution  of  calcium  sulphate    is   added  to  solutions 
of  tartaric  acid  and  racemic  acid  respectively.     On  the  follow- 
ing day,  calcium  racemate  is  precipitated,  but  calcium  tartrate 
remains  dissolved. 

10.  "Tartar    Emetic.  "—A  solution    of    potassium  hydrogen 
tartrate    is  prepared  by  dissolving  1  g.  of  tartaric  acid  in  a 
small  quantity  of  water,  neutralizing  with  potassium  hydroxide, 
and  adding  a  concentrated  solution  of  a  second  gramme  of 
tartaric  acid.     The  precipitated  potassium  hydrogen  tartrate 
is  redissolved  by  heating,  after  addition  of  a  little  water.     To 
this  solution  is  added  antimony  oxide;    it  dissolves,  forming 
"  tartar  emetic." 

CITRIC   ACID  (197). 

11.  Preparation  from  Lemons. — A  small  quantity  of  water  is 
added  to  10  c.c.  of  lemon-juice,  the  mixture  filtered,  and  made 
alkaline  with  ammonium  hydroxide.     On  addition  of  calcium 


34    LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [XVIL 

chloride,  no  precipitate  is  formed;  on  boiling  the  mixture, 
tricalcium  citrate  is  precipitated,  and  is  redissolved  as  the 
liquid  cools. 

12.  Action  of  Concentrated  Sulphuric  Acid  on  Citric  Acid. — 
A  solution  of  5  g.  of  citric  acid  in  cold,  concentrated  sulphuric 
acid  is  heated  in  a  distilling-flask,  fitted  with  a  delivery-tube. 
The   carbon  monoxide  evolved  is  identified  by  the  method 
described  in  IX.,  3. 

13.  Formation  of  Acetone  from  Citric  Acid. — A  solution  of 
0-5  g.  of  citric  acid  in  a  small  quantity  of  water  is  heated  to 
80°,  and  a  few  drops  of  a  2  per  cent,  solution  of  potassium 
permanganate    added.     The    colour    is    rapidly    discharged. 
After  filtration,  the  liquid  is  saturated  with  ammonia,  and  a 
solution   of  iodine   added.     lodoform   is  produced   from   the 
acetone  formed  by  the  oxidation. 

XVII.    CHLORAL  HYDRATE. 

(201.) 

1.  Action  of  Water  on  Chloral. — 3  g.  of  chloral  hydrate  are 
covered  with  concentrated  sulphuric  acid,   and  the  mixture 
agitated.     An  oily  layer  of  anhydrous  chloral  collects  on  the 
surface  of  the  acid.      This  is  separated  from  the  sulphuric 
acid  by  the  aid  of  a  50-c.c.  tap-funnel,  and  brought  into  con- 
tact with  a  small  quantity  of  water;  heat  is  evolved,  and  solid 
chloral  hydrate  formed. 

2.  Action  of  Alkali  Hydroxide  on  Chloral  Hydrate. — A  small 
quantity  of  potassium-hydroxide  solution  is  added  to  1  g.  of 
chloral  hydrate  dissolved  in  10  c.c.  of  water.     The  odour  of 
chloroform  becomes  perceptible,   and  the  liquid  is  rendered 
turbid  by  the  separation  of  minute  drops  of  this  substance. 
The  presence  of  formic  acid  in  the  solution  is  proved  by  warm- 
ing it,   after  careful  neutralization  and  addition  of  a  small 
quantity  of  mercuric  chloride  or  silver  nitrate  (IX.,  2). 


xvm.]    ALDEHYDO-ALCOHOLS  AND  KETO-ALCOHOLS        35 

3.  Silver-mirror  Test  for  Chloral  Hydrate. — A  dilute  solution 
of  chloral  hydrate  is  warmed  in  a  test-tube  on  a  water-bath 
with  a  small  quantity  of  an  ammoniacal  solution  of  silver 
nitrate,  prepared  in  accordance  with  the  method  described  in 
X.,  2.     If  the  tube  is  clean,  a  silver  mirror  is  deposited  on  its 
sides. 

4.  Action  of  Sodium  Hydrogen  Sulphite  on  Chloral  Hydrate. — 
A  concentrated  solution  of  sodium  hydrogen  sulphite  is  poured 
over   3   g.    of   chloral   hydrate,    and   the   mixture   vigorously 
agitated.     The  hydrate  at  first  dissolves,  but  the  liquid  soon 
becomes  a  thick  paste,  owing  to  separation  of  the  addition- 
product. 


XVIII.    ALDEHYDO-ALCOHOLS  AND  KETO-ALCOHOLS  OR 

SUGARS. 

(202-228.) 
PROPERTIES  OF  THE  MONOSES  (203). 

1.  Silver-mirror  Test. — A  ten  per  cent,  solution  of  dextrose  is 
warmed  in  a  clean  test-tube  in  a  water-bath  with  an  ammoniacal 
solution   of   silver   nitrate   prepared   as   in   X.,    2.      A   silver 
mirror  forms  on  the  inner  surface  of  the  test-tube. 

2.  Resinification  with  Caustic  Alkalis. — A  similar  solution  is 
boiled  with  a  small   amount    of  a  solution  of  potassium  or 
sodium   hydroxide.     The   liquid   turns   yellow,    then   brown, 
and  finally  resinifies. 

3.  Reduction  of  FEHLING'S  Solution. — On  heating  another 
portion   of   the    dextrose    solution   with    FEHLING'S    solution 
(XVI.,    6),    reduction     takes     place,    with    formation    of    red 
cuprous  oxide. 

4.  Osazones. — A  solution  of  phenylhydrazine  in  sulphurous 
acid  is  added  to  another  portion  of  the  dextrose  solution  in  a 
test-tube.     On  warming  the  mixture  in  a  water-bath,  phenyl- 


36     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [xvm. 

glucosazone  precipitates  in  the  form  of  microscopic,  yellow 
needles. 

METHODS  OF  FORMATION  OF  THE  MONOSES  (206). 

5.  Inversion  of  Sucrose  (Cane-sugar). — A  dilute  solution  of 
sucrose  is  boiled  for  several  minutes  with  a  few  drops  of  dilute 
sulphuric  acid.     After  this  treatment,  the  solution  answers  to 
the  dextrose-tests  described  in  1-4. 

6.  Glycerose. — A  mixture  of  10  g.  of  glycerol  and  20  c.c.  of 
nitric  acid  of  1-18  specific  gravity  is  heated  in  a  beaker  on  the 
water-bath  until  oxides  of  nitrogen  are  evolved,  and  cooled 
quickly.     After  neutralization  of  the  solution  with  potassium 
or  sodium  hydroxide  the  presence  of  glycerose  can  be  demon- 
strated by  reactions  1-4. 

PENTOSES  (207). 

7.  Furfuraldehyde-Test. — To  10  g.  of  bran   contained  in  a 
half-litre  flask  is  added  a  mixture  of  5  g.  of  concentrated  sul- 
phuric acid  and  70  c.c.  of  water.     The  flask  is  connected  with  a 
condenser,  and  heated.     The  distillate  contains  furfur  aldehyde 
(393),   characterized  by  its  odour.     The  smell  of  fresh  rye- 
bread  is  due  to  the  presence  of  furfuraldehyde.     This  aldehyde 
can  be  identified  in  two  ways. 

a)  On  addition  of  a  small  quantity  of  aniline  to  the  solu- 
tion, followed  by  concentrated  hydrochloric  acid,  the  liquid 
acquires  an  intense  red  colour. 

b)  A   solution  of  phenylhydrazine  in  sulphurous   acid   is 
added   to  the  mixture  containing  furfuraldehyde,  whereupon 
furfuraldehyde-hydrazone  is  precipitated  in  the  form  of  an 
oil,  which  soon  crystallizes. 

HEXOSES   (208). 

8.  Hydrochloric-acid  Test. — A  solution  of  a  hexose  is  boiled 
with   concentrated    hydrochloric   acid.      The   liquid   becomes 


xvm.]    ALDEHYDO-ALCOHOLS  AND  KETO-ALCOHOLS        37 

brown  and  deposits  "  humic  substances  ";  Isevulic  acid  remains 
in  solution  (234). 

Dextrose   (208). 

9.  Calcium  Alkoxide  of  Dextrose. — Milk  of  lime  is  added 
drop  by  drop  to  10  c.c.  of  a  solution  of  1  part  of  dextrose  in  2 
parts  of  water,  and  the  mixture  agitated.     The  lime  dissolves, 
forming  the  calcium  alkoxide  or  saccharate  of  dextrose.     This 
is  decomposed  by  carbon  dioxide,  with  precipitation  of  calcium 
carbonate. 

10.  Glucosesulphuric  Acid. — 1  g.  of  dextrose  is  triturated 
in  a  mortar  with  cold,   concentrated  sulphuric  acid,   added 
drop    by    drop    till    solution    is  complete.     Glucosesulphuric 
acid  is  formed,  and  can  be  detected  by  diluting  with  water, 
adding  barium  carbonate  until  the  mixture,  thoroughly  blended 
by  the  aid  of  the  pestle,  ceases  to  be  acid,  and  filtering;  the 
filtrate    contains   the    barium    salt   of   glucosesulphuric    acid. 
Addition    of   dilute   sulphuric    acid    decomposes    the   barium 
glucosesulphate,  precipitating  barium  sulphate. 

11.  Copper  Alkoxide  of  Dextrose. — A   small    quantity  of  a 
solution  of  one  part  of  dextrose  in  2  parts  of  water  is  added  to 
2  c.c.  of  ten  per  cent,  solution  of  copper  sulphate.     On  addi- 
tion of  potassium  hydroxide  to  the  mixture,  no  precipitate 
is  formed,   the  formation  of  a  copper  alkoxide   of   dextrose 
imparting  a  dark-blue  colour  to  the  solution. 

12.  Detection  of  Dextrose  in  Urine. — A  bismuth  solution, 
prepared   by  mixing  solutions   of  bismuth   nitrate,   Rochelle 
salt,  and  sodium  hydroxide,  is  added  to  a  2  per  cent,  solution 
of    dextrose,    and    the    mixture    boiled.     Black    bismuthous 
oxide,  BiO,  is  precipitated. 

13.  Oxidation   of   Dextrose  by  Nitric  Acid. — A  mixture   of 
1  g.  of  dextrose  and  10  c.c.  of  nitric  acid  of  1-3  specific  gravity 
is  evaporated  to  dryness  on  the  water-bath.     About  1  c.c.  of 
water  is  added  to  the  residue,  and  5  c.c,  of  a  concentrated 


38    LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [xvm. 

solution  of  potassium  acetate.     After  a  short  time,  potassium 
hydrogen  saccharate  is  precipitated. 

L  ae  v  u  1  o  s  e  (209.) 

14.  Alcoholic    Character. — The   alcoholic    character  of  this 
compound  can  be  demonstrated  by  the  methods  employed  for 
dextrose  (9-11). 

15.  Test   for  Laevulose. — 1  c.c.  of  a  ten  per  cent,  solution 
of  Isevulose  is  heated  with  concentrated  hydrochloric  acid  and 
some  crystals  of  resorcinol.     The  liquid  turns  dark-red. 

d-Galactose  (211). 

1 6.  Oxidation  of  d-Galactose  to  Mucic  Acid. — A  solution  of 
1  g.  of  d-galactose  is  boiled  for  several  minutes  with  nitric  acid 
of  1*3  specific  gravity,  evaporated  to  small  bulk,  diluted  with 
water,   and   cooled.     Mucic   acid   separates   as   a   crystalline 
powder,  soluble  with  difficulty  in  cold  water.     If  d-galactose 
cannot  be  obtained,  lactose  should  be  used  instead  (215). 

A  small  quantity  of  the  mucic  acid  is  washed  with  water, 
and  a  trace  of  it  introduced  into  a  drop  of  five  per  cent, 
potassium-hydroxide  solution  on  a  microscope-slide.  Under 
the  microscope,  the  characteristic,  prismatic  crystals  of  potas- 
sium mucate  make  their  appearance  after  a  few  moments. 

HEXODIOSES   (213-220) 

Lactose  (215). 

17.  Detection  of  Lactose  in  Milk. — A  few  drops  of  dilute 
acetic  acid  are  added  slowly  to  25  c.c.  of  milk  diluted  with  a 
like  volume  of  water,  the  liquid  being  thoroughly  mixed  by 
stirring.     The  casein  and  fatty  constituents  of  the  milk  are 
thus  precipitated.     The  mixture  is  filtered  through  a  folded 
filter.     On  warming  part  of  the  filtrate  with  FEHLING'S  solu- 
tion,   the   lactose    causes   reduction,    with   formation   of   red 


xvm.]    ALDEHYDO-ALCOHOLS  AND  KETO-ALCOHOLS        39 

cuprous  oxide.  The  rest  of  the  filtrate  is  evaporated  with 
dilute  nitric  acid  to  small  bulk;  d-galactose  is  formed  by 
inversion,  and  oxidized  to  mucic  acid,  which  can  be  recognized 
by  the  method  of  16. 

18.  Lactosazone. — On  warming   5  c.c.   of   a  ten  per  cent, 
solution  of  lactose  with  a  sulphurous-acid  solution  of  phenyl- 
hydrazine,  an  osazone — phenyllactosazone — is  formed. 

19.  "  Sand-sugar." — The  taste  of  lactose  is  not  so  sweet  as 
that  of  sucrose,  and  in  the  mouth  it  resembles  sand,  hence  the 
name  sand-sugar. 

Sucrose  (216-220). 

20.  Properties  Distinguishing  Sucrose  from  the  Monoses. — 

When  heated  with  caustic  alkalis,  a  ten  per  cent,  solution  of 
sucrose  does  not  resinify;  it  does  not  reduce  FEHLING'S  solu- 
tion; and,  when  warmed  with  a  solution  of  phenylhydrazine 
in  sulphurous  acid,  gives  no  osazone  (1-4). 

21.  Action  of  Heat  on  Sucrose. — On  heating  a  small  quantity 
of  sucrose  in  a  test-tube,  it  turns   brown,    forming   caramel, 
and  evolving  the  characteristic  odour  of  this  substance. 

22.  Tricalcium  Saccharate. — 10  c.c.  of  a  twenty  per    cent, 
solution  of  sucrose  are  agitated  with  sufficient  milk  of  lime  to 
cause  permanent  turbidity,   and  filtered.     When  the  filtrate 
is  boiled,  the  nearly  insoluble  tricalcium  saccharate,  with  the 
formula   Ci2H220n,3CaO,3H20,    is   precipitated;    on   cooling 
it  is  dissolved. 

23.  Inversion. — A  solution  of  2  g.  of  sucrose  is  inverted  by 
boiling  for  several  minutes  with  dilute  sulphuric  acid.     After 
careful   neutralization   with   sodium   hydroxide,    the   solution 
thus  obtained  has  the  properties  characteristic  of  monoses, 
described  in  1-4,  and  answers  to  the  Isevulose-test  with  resor- 
cinol. 


40    LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [xvm. 

POLYOSES   (224-228.) 

Starch  (225  and  226). 

24.  Starch-paste. — 5  g.  of  powdered  starch  are  washed  with 
water  on  a  filter-paper.     The  washed  starch  is  transferred  to  a 
beaker  containing  200  c.c.  of  boiling  water,  a  faintly  opalescent 
solution  of  starch-paste  being  obtained. 

25.  Properties   Distinguishing   Starch   from   the    Monoses. — 
If  the  starch  has  been  washed  with  sufficient  care,  this  starch- 
paste  does  not  reduce  FEHLING'S  solution,  and  is  not  resinified 
by  alkalis. 

26.  Conversion  of  Starch  into  Dextrose. — a)  50  c.c.  of  the 
starch-paste  solution  are  boiled  with  10  c.c.  of  ten  per  cent, 
sulphuric  acid  for  fifteen  minutes.     After  neutralization  with 
sodium  hydroxide,  the  liquid  has  the  properties  characteristic 
of  monoses  described  in  1-4. 

6)  A  mixture  of  50  c.c.  of  the  starch-paste  with  10  c.c. 
of  fresh  malt-extract,  which  contains  diastase,  is  heated  at 
60°  for  about  half  an  hour.  The  paste  becomes  liquefied,  and 
the  liquid  no  longer  answers  to  the  iodine-test. 

27.  Iodine-test  for  Starch. — A  trace  of  an  iodine  solution  is 
added  to  one  of  starch-paste,   a  deep-blue  coloration  being 
produced.     On  heating,  this  disappears,  but  on  cooling  returns, 
provided  the  heating  is  not  too  prolonged. 

28.  Barium    Alkoxide    of    Starch. — A    solution    of    barium 
hydroxide  is  added  to  a  boiling  solution  of  starch-paste.     The 
barium  alkoxide  of  starch  is  precipitated. 

29.  Conversion  of  Starch  into  Dextrin. — a)  A  small  quantity 
of  starch  is  heated  carefully  in  a  test-tube,  the  residue  agitated 
with  cold  water,  and  filtered.      The  filtrate  contains  dextrin, 
proved  by  the  yellow  coloration  developed  by  heating  with 
alkalis,  its  precipitation  from  solution  on  addition  of  alcohol, 
and  the  red  colour  produced  by  addition  of  iodine  solution. 

6)  50  c.c.  of  concentrated  hydrochloric  acid  is  added  to 
5  g.  of  starch,  the  mixture  becoming  rapidly  converted  into 


xvm.]    ALDEHYDO-ALCOHOLS  AND  KETO-ALCOHOLS       41 

a  transparent,  opalescent  paste.  After  the  lapse  of  one  or 
two  hours,  the  paste  will  have  liquefied,  and  on  the  following 
day  will  no  longer  answer  to  the  iodine-test  for  starch,  although 
it  will  still  show  the  reactions  of  dextrin.  A  few  days  later, 
the  liquid  will  only  contain  dextrose. 

30.  Potato-starch. — A   small   quantity    of  potato-starch   is 
moistened  with  a  few  drops  of  water,  a  little  of  the  mixture 
transferred  to  a  microscope-slide,   and  examined  under  the 
microscope.     The  starch-granules  are  seen  to  have 'a  charac- 
teristic shell-like  appearance  (225,  Fig.  69). 

Cellulose  (227  and  228). 

31.  Hydrolysis  of  Cellulose. — A  piece  of  filter-paper  is  dis- 
solved in  cold,   concentrated  sulphuric  acid  by  the  method 
described  in  10,  the  solution  poured  into  water,  and  boiled  for 
half  an  hour.     When  neutralized  with  sodium  hydroxide,  it 
answers  to  the  tests  for  monoses  (1-4). 

32.  Parchment-paper. — A  strip  of  filter-paper  is  immersed 
in  sulphuric  acid  containing  half  its  volume  of  water,  and  at 
once  transferred  to  a  large  quantity  of  cold  water,  and  thor- 
oughly washed.     This  treatment  converts  the  cellulose  into 
amyloid  or  parchment-paper,  which  gives  a  blue  coloration 
with  iodine.     Although  wet,  the  parchment-paper  is  very  tough, 
and  cannot  be  torn  readily. 

33.  Solubility  of  Cellulose  in  SCHWEITZER'S  Reagent. — An 
ammoniacal  solution  of  copper  oxide  is  prepared  by  adding 
freshly-precipitated,  washed  copper  hydroxide  to   10  c.c.   of 
concentrated    ammonium   hydroxide   till   no   more   dissolves. 
When  placed  in  this  solution,  filter-paper  (cellulose)  dissolves. 
On  addition  of  dilute  hydrochloric  acid,  the  colour  is  discharged, 
and  an  amorphous,  flocculent  precipitate  of  cellulose  deposited. 

34.  Nitrocelluloses. — A    small     piece     of     cotton-wool     is 
immersed  for  several  seconds  in  a  cold  mixture  of  one  part 
of  concentrated  nitric  acid  and  two  parts  of  concentrated 


42    LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY    [xix. 

sulphuric  acid,  nitre-celluloses  being  formed.  It  is  then 
washed  carefully  with  much  cold  water,  and  dried  at  the  ordi- 
nary temperature.  A  part  held  with  tongs  in  a  Bunsen  flame 
burns  energetically.  Another  portion  is  agitated  with  a  mix- 
ture of  alcohol  and  ether,  and  the  liquid — named  collodion — 
poured  on  a  glass  plate;  on  evaporation  of  the  solvent,  a 
transparent  skin  is  left. 

The  remainder  of  the  nitrocelluloses  is  moistened  with  a 
small  quantity  of  ethyl  acetate.  A  gelatinous  mass  is  formed, 
which,  when  dry,  burns  slowly  ("smokeless  powder "). 

35.  Detection  of  Lignin  in  Paper. — A  sheet  of  paper  is 
coated  with  a  solution  of  aniline  in  hydrochloric  acid.  If 
made  from  wood,  the  paper  acquires  an  intense  yellow  colour. 


XIX.    PROTEINS. 
(246-254.) 

1.  Detection    of   Nitrogen   and    Sulphur   in   the   Proteins.— 
A  few  cubic  centimetres  of  a  solution  of  egg-albumin — prepared 
by  dissolving  white-of-egg  in  five  times  its  volume  of  water — 
is  heated  with  potassium  hydroxide.     Ammonia  is  evolved, 
and  can  be  detected  by  the  aid  of  a  moist  strip  of  red  litmus- 
paper. 

The  liquid  is  diluted  with  water,  and  lead  acetate  added. 
The  potassium  sulphide  formed  in  the  last  experiment  reacts 
with  the  lead  salt,  precipitating  black  lead  sulphide. 

2.  "  Salting-out  "  Proteins  with  Ammonium  Sulphate. — Solid 
ammonium  sulphate  is  added  to  20  c.c.  of  the  egg-albumin 
solution.     The  albumin  is  precipitated. 

3.  Coagulation  of  Proteins  by  Alcohol. — Strong  alcohol  added 
to  a  solution  of  egg-albumin  gives  a  precipitate  of  coagulated 
egg-albumin.     A  similar  precipitate  is  formed  when  an  aqueous 
solution  of  egg-albumin  is  boiled.     Coagulated  egg-albumin 


xx.]  HYDROCYANIC  ACID  43 

is  soluble  in  dilute  caustic  alkali,  concentrated  hydrochloric 
acid,  and  concentrated  sulphuric  acid. 

4.  Coagulation  of  Proteins  by  Nitric  Acid. — Dilute  nitric  acid 
is  added  to  an  egg-albumin  solution  prepared  by  the  method 
of  i.     The  egg-albumin  is  precipitated. 

5.  Biuret-reaction. — A  few  drops  of  copper-sulphate  solu- 
tion are  added  to  5  c.c.  of  a  solution  of  egg-albumin.     Careful 
addition  of  dilute  potassium  hydroxide  to  the  mixture  pre- 
cipitates copper  albuminate.     Excess  of  potassium  hydroxide 
redissolves  the  precipitate,  producing  a  violet-red  coloration. 

6.  MiLLON'S  Reagent. — On  boiling  an  egg-albumin  solution 
with  MILLON'S  reagent — a  solution  of  mercuric  nitrate  con- 
taining nitrous  acid — a  red,  coagulated  mass  is  obtained. 

7.  Xanthoprotem-reaction. — When  an  egg-albumin  solution 
is  warmed  with  dilute  nitric  acid,  it  coagulates,  with  produc- 
tion of  a  yellow  coloration. 

8.  ADAMKIEWICZ'S  Reaction. — With  concentrated  sulphuric 
acid  a  solution  of  egg-albumin  in  glacial  acetic  acid  yields  a 
violet  coloration,  due  to  the  presence  in  the  mixture  of  a  small 
proportion  of  glyoxylic  acid. 

9.  Decomposition-products  of  Keratin. — A  feather  is  heated 
with  concentrated  potassium  hydroxide.     It  dissolves,  and  the 
solution  thus  obtained  gives  the  reactions  for  nitrogen  and 
sulphur,  described  in  i.  CALIFORNIA     COLl 

of   PHARMACY 

XX.    HYDROCYANIC    ACID,    AND    ITS    SIMPLE    AND 
COMPLEX   SALTS. 

(256  and  257.) 

i.  Hydrocyanic  Acid. — 10  c.c.  of  a  cold,  saturated  solution 
of  potassium  ferrocyanide  are  poured  into  a  distilling-flask 
connected  with  a  condenser,  and  20  c.c.  of  twenty  per  cent, 
sulphuric  acid  added.  The  open  end  of  the  condenser  is 
dipped  into  a  test-tube  containing  water  and  a  few  drops  of 


44     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY     [xx. 

concentrated  potassium  or  sodium  hydroxide.  On  heating, 
hydrocyanic  acid  distils,  and  is  converted  into  potassium 
cyanide. 

2.  Prussian-blue  Test. — A  mixture  of  a  ferrous  salt  and  a 
ferric  salt  is  added  to  part  of  the  solution  obtained  in  the 
last    experiment.     On    acidifying   with    hydrochloric    acid,    a 
precipitate  of  Prussian  blue  is  formed  (I.,  3  a). 

3.  Silver    Cyanide. — A  drop  of  a  dilute  solution  of  silver 
nitrate  is  added  to  10  c.c.  of  a  solution  of  1  g.  of  potassium 
cyanide  in  100  c.c.  of  water.     On  agitating  the  mixture,  the 
precipitate  first  formed  redissolves,  yielding  a  double  cyanide 
of  potassium  and  silver,  KAg(CN)2.     On  further  addition  of 
silver  nitrate,  a  permanent  precipitate  of  silver  cyanide,  AgCN, 
is  obtained. 

4.  Hydrolysis  of  Potassium  Cyanide. — 25  c.c.  of  the  solution 
of  potassium  cyanide  prepared  for  experiment  3  are  boiled  in  a 
flask.     The  evolved  ammonia  turns  a  strip  of  red  litmus-paper 
blue. 

5.  Conversion  of  Ammonium  Formate  into  Hydrocyanic  Acid. 
—3  g.  of  ammonium  formate  are  submitted  to  dry  distillation 
in  a  small  distilling-flask  connected  with  a  condenser  dipping 
into   a  test-tube   with   very   dilute   sodium   hydroxide.     The 
presence  of  hydrocyanic  acid  in  the  distillate  can  be  demon- 
strated by  the  Prussian-blue  test  (2). 

6.  Double  Ferrocyanide  of  Potassium  and  Calcium. — A  small 
quantity  of  a  calcium-chloride  solution  is  added  to  a  cold, 
saturated   solution    of   potassium   ferrocyanide.     The   double 
ferrocyanide,  K2CaFe(CN)e,  is  precipitated. 

7.  Ferrocyanic    Acid. — Concentrated    hydrochloric    acid    is 
added  to  5  c.c.  of  a  strong  solution  of  potassium  ferrocyanide. 
White  ferrocyanic  acid,   H4Fe(CN)6,  is  precipitated.     When 
collected  on  a  filter-paper,  it   soon  turns   blue,  Prussian  blue 
being  formed  by  decomposition  and  oxidation. 

8.  Action    of    Concentrated    Sulphuric    Acid    on    Potassium 
Ferrocyanide. — 5   g.    of   potassium    ferrocyanide    are   warmed 


xxi.]         POTASSIUM  CYANATE  AND  THIOCYANATE  45 

with  concentrated  sulphuric  acid  in  a  fractionating-flask. 
The  evolved  carbon  monoxide  can  be  identified  by  the  method 
described  in  IX.,  3. 

9.  Action  of  Heat  on  Potassium  Ferrocyanide. — 2  g.  of  potas- 
sium ferrocyanide  are  heated  to  redness  in  a  crucible;    when 
cold,  the  residue  is  lixiviated  with  water,   and  the  mixture 
filtered  quickly.     The  solution  contains  potassium  cyanide,  as 
can  be  proved  by  the   Prussian-blue  and   silver-nitrate  tests 
(2  and  3). 

10.  Potassium    Ferricyanide.- — Bromine-water  is  added  to 
a  solution  of  potassium  ferrocyanide,  which  converts  it  into 
potassium  ferricyanide.     This  change  is  detected  by  addition 
of  ferric  chloride,  which  produces  a  brown  coloration,  instead 
of  a  precipitate  of  Prussian  blue. 

11.  Reduction    of   Potassium  Ferricyanide. — Litharge,  PbO, 
is  added  to  a  solution  of  potassium  ferricyanide  containing 
potassium   hydroxide.     The   solid   becomes   brown,    the   lead 
monoxide  being  oxidized  to  lead  dioxide,  PbC>2.     After  filter- 
ing, and  adding  ferric  chloride  to  the  filtrate,  a  precipitate  of 
Prussian  blue  is  formed,  proving  the  presence  of  potassium 
ferrocyanide. 

12.  Oxidation  of  Potassium  Ferrocyanide  by  Potassium  Per- 
manganate.— Sulphuric  acid  is  added  to  a  dilute  solution  of 
potassium  ferrocyanide.     This  mixture  decolorizes  potassium 
permanganate,   forming  potassium   ferricyanide,   which   gives 
a  brown  coloration  with  ferric  chloride. 


XXI.    POTASSIUM  CYANATE  AND  POTASSIUM 
THIOCYANATE. 

(258-260.) 

i.  Potassium  Cyanate. — Litharge,  PbO,  is  added  to  3  g.  of 
fused  potassium  cyanide  in  a  crucible  so  long  as  reduction  to 
metallic  lead  is  rapid.  The  potassium  cyanate,  KCNO,  formed 


46    LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY    [xxn. 

is  extracted  with  cold  water.  On  addition  of  sulphuric  acid, 
carbon  dioxide  is  evolved,  since  the  liberated  cyanic  acid 
reacts  at  once  with  the  water  to  form  carbon  dioxide  and 
ammonia.  The  liquid  in  the  flask  is  made  alkaline  with 
sodium  hydroxide,  and  heated.  The  evolved  ammonia  turns 
blue  a  strip  of  moist,  red  litmus-paper  held  in  the  mouth  of 
the  flask. 

2.  Potassium    Thiocyanate.— 10  c.c.   of   potassium-cyanide 
solution  are  boiled  for  some  minutes  with  "  flowers  of  sulphur  " 
and  filtered.     Addition  of  ferric   chloride  to  the  filtrate  gives 
a  blood-red   coloration,   proving  the  formation   of  potassium 
thiocyanate. 

3.  Silver    Thiocyanate. — With   silver  nitrate  a  solution  of 
potassium  thiocyanate  produces  a  white,  cheese-like  precipi- 
tate of  silver  thiocyanate,  AgCNS,  insoluble  in  dilute  nitric 
acid. 


XXII.    DERIVATIVES   OF  CARBONIC  ACID. 

(263-270.) 
CARBON  BISULPHIDE  (264). 

1.  Inflammability. — A  few  drops  of  carbon  disulphide  are 
poured  into  a  porcelain  basin,  and  ignited.     The  liquid  burns 
with  a  blue  flame,  forming  carbon  dioxide  and  sulphur  dioxide, 
the  presence  of  the  latter  being  made  evident  by  its  character- 
istic, suffocating  odour. 

2.  Volatility. — On   blowing   upon    a  few   drops  of   carbon 
disulphide  in  the  palm  of  the  hand,  a  sensation  of  cold  is  expe- 
rienced. 

3.  Solvent    Power. — Some  linseed  is  crushed  in  a  mortar, 
transferred  to  a  test-tube,  and  covered  with  a  small  quantity 
of  carbon  disulphide.     After  about  a  minute,   the  liquid  is 
poured  on  a  clock-glass  or  watch-glass,  and  allowed  to  evapo- 
rate spontaneously.    The  residue  is  linseed  oil. 


xxii.]  DERIVATIVES  OF  CARBONIC  ACID  47 

4.  Barium    Trithio carbonate. — 5  g.  of  barium  sulphide  are 
L  oiled  with  water  for  a  few  seconds,  and  the  mixture  filtered. 
About  1  c.c.  of  carbon  disulphide  is  added  to  the  warm  fil- 
trate, the  mixture  vigorously  shaken,  and  allowed  to  cool.     A 
yellow  precipitate  of  barium  trithiocarbonate  is  deposited. 

5.  Potassium  and  Copper  Salts  of  Xanthic  Acid. — 10  c.c.  of  a 
twenty  per  cent,  solution  of  potassium  hydroxide  in  absolute 
alcohol  is  agitated  with  successive  quantities  of  carbon  disul- 
phide, till  potassium  xanthate  separates  out.     The  precipita- 
tion of  the  salt  is  facilitated  by  addition  of  a  small  amount 
of  ether.     It  is  collected  on  a  filter,  dried  between  layers  of 
filter-paper,   and  dissolved  in  water.     On  adding  a  solution 
of   copper   sulphate,    a  brownish-black   precipitate   of   cupric 
xanthate  is  formed.     This  substance  changes  so  quickly  to 
yellow  cuprous  xanthate  as  to  render  its  formation  hardly 
perceptible.     In  a  dilute  solution  of  the  xanthate  the  reaction 
is  much  slower. 

UREA  (266  and  267). 

6.  WOHLER'S   Synthesis. — Potassium  cyanate,  prepared  by 
the  method  of  XXI.,  i,  is  dissolved  in  water.     Ammonium  sul- 
phate is  added,  producing  potassium  sulphate  and  ammonium 
cyanate.     The  solution  is  evaporated  almost  to  dryness  on 
the  water-bath,  and  the  urea  formed  by  the  intramolecular 
rearrangement    of    the    ammonium    cyanate    extracted    with 
alcohol.     The  solvent  is  distilled,  leaving  a  residue  of  urea. 

7.  Urea  Oxalate. — The  urea  obtained  in  the  last  experiment 
is  dissolved  in  a  very  small  quantity  of  water,  and  a  concen- 
trated solution  of  oxalic  acid  added.     A  crystalline  precipitate 
of  urea  oxalate  is  deposited. 

8.  Urea   Nitrate    from    Urine. — About  10  c.c.  of  urine  are 
evaporated  to  small  bulk  on  a  water-bath,  and  the  residue 
allowed  to  cool.     On  addition  of  a  few  cubic  centimetres  of 
colourless  nitric  acid  of  1*4  specific  gravity,  a  precipitate  of 
urea  nitrate  is  formed.    The  mother-liquor  is  poured  off,  and 


48    LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [xxn. 

the  nitrate  purified  by  crystallization  from  a  small  quantity 
of  hot  water. 

9.  KNOP'S  Method  for  the  Estimation  of  Urea  in  Urine. — A  so- 
lution of  bromine  in  cold  potassium  hydroxide  is  added  to  10  c.c. 
of  urine  contained  in  a  distilling-flask  fitted  with  a  delivery- 
tube.    The  urea  at  once  begins  to  decompose,  evolving  nitrogen, 
which  is  collected  over  water,  and  tested  with  a  lighted  taper. 

10.  BUNSEN'S  Method  for  the  Estimation  of  Urea  in  Urine.— 
10  c.c.  of  urine  are  heated  with  baryta-water  in  a  flask.     A 
strip  of  red  litmus-paper  held  in  the  mouth  of  the  flask  is  turned 
blue  by  the  ammonia  liberated.     At  the  same  time,  the  precip- 
itated barium  carbonate  renders  the  liquid  turbid. 

11.  LiEBlG'S  Method  for  the  Estimation  of  Urea  in  Urine. — 
A  solution  of  mercuric  nitrate  is  added  to  10  c.c.  of  a  two  per 
cent,  solution  of  urea.     A  white  precipitate  of  the  composition 
2CON2H4,Hg(N03)2,3HgO  is  formed.     When   excess    of   the 
mercuric  nitrate  has  been  added,  a  drop  of  the  solution  brought 
into  contact  with  one  of  sodium  carbonate  gives  a  yellow 
precipitate  of  basic  nitrate  of  mercury. 

12.  Action  of  Heat  on  Urea. — 1  g.  of  urea  is  carefully  heated 
in  a  test-tube;    it  melts,  and  evolves  ammonia,  which  can  be 
identified   by   means   of   a   strip   of   red   litmus-paper.     The 
fused  mass  soon  re-solidifies,  and  the  heating  is  stopped.     The 
residue  is  lixiviated  with  a  small  quantity  of  cold  water,  biuret 
going  into  solution.     This  substance  can  be  identified  by  the 
biuret-reaction.    Potassium  hydroxide  and  one  or  two  drops  of  a 
ten  per  cent,  solution  of  copper  sulphate  are  added  to  the  liquid; 
the  violet-red  coloration  produced  is  due  to  the  formation  of  a 
copper  compound  of  biuret. 

13.  Cyanuric    Acid. — This  substance  is   the  principal  con- 
stituent of  the  residue  in  the  test-tube  after  solution  of  the 
biuret  in  the  last  experiment.     It  is  dissolved  in  warm  water; 
after   cooling,   addition   of   copper   sulphate   and   ammonium 
hydroxide   gives   a    crystalline,    violet    precipitate    of    copper 
ammonium  cyanurate. 


xxiii.]  URIC  ACID  GROUP  49 

CARBAMIC  ACID  (268). 

14.  Calcium    Carbamate. — Ammonium    hydroxide  is  added 
to  10  c.c.  of  a  ten  per  cent,  solution  of  calcium  chloride.     On 
passing  carbon  dioxide  through  the  mixture,  no  precipitate  is 
obtained,  the  calcium  carbamate  formed  being  soluble  in  water. 
When   the   solution  is   warmed,   the   carbamate   decomposes, 
precipitating  calcium  carbonate. 

15.  Ammonium  Dithiocarbamate. — A   drop  of  carbon  disul- 
phide  is  added  to  a  concentrated  alcoholic  solution  of  ammonia 
contained  in  a  porcelain  dish,  and  the  mixture  is  evaporated  to 
dryness  on  a  water-bath.     The  initial  product  formed  is  ammo- 
nium   dithiocarbamate.     It  is   decomposed   by  the  excess  of 
ammonia  present  into  ammonium  thiocyanate  and  ammonium 
sulphide.    The  sulphide  volatilizes,  and  the  presence  of  the  thio- 
cyanate in  the  residue  is  detected  by  dissolving  it  in  water,  and 
adding  a  few  drops  of  dilute  hydrochloric  acid  and  ferric  chloride. 
The  formation  of  ferric  thiocyanate  produces  a  blood-red  color- 
ation. 

XXIII.     URIC   ACID    GROUP. 

(271-273.) 

1.  Ammonium    Urate. — A  mixture  of  50  c.c.  of  urine  and 
2-5  c.c.   of  a  concentrated  solution  of  sodium  carbonate  is 
placed  in  a  flask,  and  5  c.c.  of  a  saturated  ammonium-chloride 
solution  added.     After  a  short  interval,  ammonium  urate  is 
precipitated. 

2.  Di-potassium   Urate. — A  small  quantity  of  uric   acid  is 
agitated  with  water;    it  does  not  dissolve.     On  addition  of 
dilute  potassium  hydroxide,  the  readily  soluble  di-potassium 
salt  is  formed,  and  can  be  reconverted  into  uric  acid  by  dilute 
acids. 

3.  Murexide-test  for  Uric  Acid. — A  few  cubic  centimetres  of 
nitric  acid  of  1-4  specific  gravity  are  added  to  0-5  g.  of  uric 
acid  in  a  porcelain  dish,  and  the  mixture  evaporated  nearly 
to  dryness  on  a  water-bath.     In  addition  to  other  products, 
alloxantine  is  formed.    When  treated  with  ammonium  hydr- 


50     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [xxiv. 

oxide,  it  forms  a  purple-red   dye — mu-rexide,  the  ammonium 
salt  of  purpuric  acid. 

4.  Reduction  of  Silver  Nitrate  by  Uric  Acid.— A  small  quan- 
tity of  uric  acid  is  dissolved  in  a  few  drops  of  sodium-carbonate 
solution.    When  the  liquid  is  brought  into  contact  with  filter- 
paper  moistened   with  a  solution   of  silver  nitrate,   a  black 
stain  of  metallic  silver  is  formed,  in  consequence  of  the  reduc- 
ing action  of  the  uric  acid. 

5.  Murexide-test   for    Caffeine. — A  few  cubic  centimetres  of 
nitric  acid  of  1  •  4  specific  gravity  are  added  to  0*5  g.  of  caf- 
feine in  a  porcelain  dish,  and  evaporated  almost  to  dryness  on 
a  water-bath.     A  yellow  stain  of  amalic  acid,  or  tetramethyl- 
alloxantine,    is    left.     On    moistening    this    with    ammonium 
hydroxide,  it  becomes  purple. 

XXIV.     BENZENE   AND   ITS   HOMOLOGUES. 
(281-288.) 

1.  Stability  of  Benzene  towards  the  Halogens. — On  agitating 
a  few  cubic  centimetres  of  benzene  with  bromine-water,  the 
bromine  is  dissolved  by  the  benzene,   but  its  colour  is  not 
discharged. 

2.  Absence  of  Double  Bonds  in  Benzene. — Benzene  is  agi- 
tated with  a  solution  of  potassium  permanganate  and  sodium 
carbonate — VON     BAEYER'S    reagent     (113     and    281).     The 
violet-red  colour  remains  unaltered. 

3.  Nitrobenzene. — 2    c.c.    of  benzene    are    added    drop    by 
drop  to  a  mixture  of  4  c.c.  of  concentrated  sulphuric  acid  and  2 
c.c.  of  nitric  acid  of  1-5  specific  gravity,  the  flask  being  cooled 
with   running  water   to   prevent   rise    of    temperature.     The 
benzene   dissolves,    and,    on   pouring   the   acid   mixture   into 
water,  nitrobenzene  separates  and  sinks  to  the  bottom.     It 
has  a  characteristic  odour,   resembling  that  of  oil  of  bitter 
almonds. 

4.  Benzenemonosulphonic     Acid. — 5    c.c.     of     benzene    are 
brought  gradually  into  contact  with  10  c.c.  of  fuming  sulphuric 


xxv]  MONOHALOGEN  COMPOUNDS  51 

acid.  At  first  heat  is  developed,  and  tlie  hydrocarbon  dis- 
solves quickly;  to  complete  the  reaction,  the  mixture  must  be 
warmed  gently.  It  is  then  poured  into  twice  its  volume  of 
water,  common  salt  added,  and  the  liquid  heated  until  hydro- 
chloric-acid gas  is  evolved.  On  cooling,  sodium  benzenesul- 
phonate  separates  in  crystalline  plates. 

5.  FRIEDEL  and   CRAFTS'S    Reaction. — 1   g.  of  aluminium 
chloride  is  added  to  5  c.c.  of  benzene,  and  a  small  quantity 
of  chloroform  dropped  into  the  mixture.     There  is  a  vigorous 
evolution  of  hydrochloric-acid  gas,   and  triphenylmethane  is 
formed. 

6.  Formation  of  Benzene  from  Calcium  Benzoate. — 10  g.  of 
calcium  benzoate  are  mixed  with  a  like  weight  of  soda-lime, 
and  heated  in  a  retort  connected  with  a  condenser.     Benzene 
distils,  and  can  be  identified  by  its  odour,  by  the  fact  that  it 
floats  on  water,  and  by  converting  it  into  nitrobenzene  with  a 
mixture  of  concentrated  nitric  and  sulphuric  acids  in  accord- 
ance with  the  method  described  in  3. 

7.  Oxidation  of  Side-chains. — 1    c.c.    of    toluene   is    heated 
with  a  solution  of  potassium  permanganate  and  sodium  car- 
bonate.    The    purple    colour    is    discharged,    and    manganese 
dioxide  precipitated,  in  consequence  of  the  oxidation  of  the 
side-chain  and  the  formation  of  benzole  acid. 

XXV.     MONOHALOGEN    COMPOUNDS. 

(289.) 

i.  Stability  of  Monochlorobenzene  towards  Alcoholic  Potash 
or  Soda. — 5  c.c.  of  monochlorobenzene  are  heated  with  10  c.c. 
of  ten  per  cent,  alcoholic  potash  or  soda  for  a  few  minutes,  and 
the  liquid  diluted  with  water.  The  monochlorobenzene  is 
precipitated  unchanged  as  an  oily  liquid.  To  prove  this,  it  is 
separated  by  means  of  a  tap -funnel,  dried  by  contact  with 
granulated  calcium  chloride  for  a  few  minutes,  and  its  boiling- 
point  determined  by  the  method  of  III.,  5.  Monochloro- 
benzene boils  at  132°. 


52    LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY    [xxvi. 

After  separation  of  the  monochlorobenzene,  the  aqueous 
liquid  is  acidified  with  nitric  acid,  and  silver  nitrate  added. 
It  does  not  become  turbid,  proving  that  the  caustic  alkali 
has  not  reacted  with  the  Cl-atom  of  the  monochlorobenzene. 


XXVI.    MONOHYDRIC  PHENOLS. 
(292-294.) 

1.  Preparation  of  Phenol  by  Fusion  of  Sodium  Benzenesul- 
phonate    with    Sodium   Hydroxide. — 10  g.  of  sodium  benzene- 
sulphonate,  3  g.  of  sodium  hydroxide,  and  a  small  quantity 
of  water  are  heated  in  an  iron  dish  to  the  temperature  of  fusion, 
the  mixture  being  continually  stirred.     When  cold,  it  i:>  dis- 
solved   in  water,    the  solution   poured  into  a  fractional  ing- 
flask,  and  dilute  sulphuric  acid  added  slowly.     Much  sulphur 
dioxide  is  evolved,  and  can  be  recognized  by  its  characteristic 
odour.     The  flask  is  connected  with  a  condenser,  and  heated. 
Phenol  distils  along  with  water,  and  is  identified  by  the  methods 
of  4  and  5. 

2.  Preparation  of  Pherol  from  Calcium  Salicylate. — 10  g.  of 
calcium  salicylate  are  heated  in  a  retort  connected  with  a  con- 
denser.    Phenol  distils,  and  can  be  recognized  by  its  odour, 
and  by  the  reactions  described  in  4  and  5. 

3.  Sodium Phenoxide. — 1  g.  of  phenol  is  agitated  with  enough 
water  to  form  an  emulsion;    on  addition  of  sodium-hydroxide 
solution,    this    dissolves,    forming   sodium   phenoxide.     When 
carbon  dioxide  is  passed  through  the  liquid  for  a  considerable 
time,  phenol  is  liberated,  and  the  mixture  rendered  turbid. 

4.  Tribromophenol. — Bromine-water    is    added    to    a    two 
per    cent,   aqueous  solution  of  phenol.      Tribromophenol  is 
precipitated. 

5.  Ferric-chloride  Test  for  Phenol. — On  addition  of  a  drop  of 
ferric-chloride  solution  to  a  one  per  cent,  solution  of  phenol, 
an  intense  violet  coloration  is  obtained. 


xxvii.]  MONOAMINO-COMPOUNDS  53 

6.  Depression   of   the   Freezing-point   of   Phenol. — 5    c.c  of 

phenol  are  melted  in  a  test-tube  by  very  careful  heating  over  a 
tiny  flame.  After  introduction  of  a  thermometer,  the  liquid  is 
allowed  to  cool.  When  crystals  begin  to  form,  the  mercury 
ceases  falling,  and  rises,  the  highest  temperature  indicated 
being  the  freezing-point.  For  anhydrous  phenol,  it  is 
39-6°. 

The  phenol  is  again  melted,  and  1  drop — about  0*05  g. — 
of  water  added.  The  freezing-point  is  determined  as  before, 
and  found  to  be  about  4°  lower. 

7.  Action  of  Nitric  Acid  on  Phenol. — A  cubic  centimetre  of 
phenol  is  added  drop  by  drop  to  10  c.c.  of  nitric  acid  of  specific 
gravity  1-3,  the  liquid  being  continually  agitated,  and  finally 
heated   to   boiling.     On   cooling,   picric   acid   is  precipitated. 
When   recrystallized   from   water,   it   is   obtained   as   yellow, 
needle-like  crystals. 

8.  Cresol. — With  bromine-water  and  ferric  chloride  respec- 
tively, an  aqueous  solution  of  cresol  gives  reactions  similar  to 
those  obtained  with  phenol  (4  and  5). 


XXVII.    MONOAMINO-COMPOUNDS  AND   THEIR 
DERIVATIVES. 

(296-301). 

i.  Aniline. — 35  c.c.  of  hydrochloric  acid  of  1-19  specific 
gravity  are  poured  into  a  flask  containing  6  g.  of  nitrobenzene, 
and  18  g.  of  tin-powder  added  in  successive  small  portions. 
To  prevent  its  contents  becoming  overheated,  the  flask  is 
shaken,  and  cooled  with  water.  The  nitrobenzene  is  reduced 
to  aniline,  this  combining  with  the  excess  of  hydrochloric  acid 
to  aniline  hydrochloride.  When  all  the  nitrobenzene  has 
dissolved,  and  its  odour  is  no  longer  perceptible,  the  aniline 
is  set  free  by  potassium  or  sodium  hydroxide,  and  the  mixture 


54    LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [xxvn. 

distilled.     The   aniline  volatilizes  with  the  steam,   rendering 
the  distillate  turbid. 

2.  Neutral  Reaction  of  Aniline. — A  small  quantity  of  aniline 
is  agitated  with  water.     The  solution  thus  prepared  neither 
imparts   a  colour  to  phenolphthalein,   nor  turns  red  litmus 
blue. 

3.  Aniline   Salts. — On  addition  of  an  acid,  the  turbid  liquid 
obtained  in  i  becomes  clear,  a  soluble  aniline  salt  being  formed. 
Potassium  or  sodium  hydroxide  reprecipitates  the  aniline  as 
an  oil. 

4.  Tribromoaniline. — With   an  aqueous   solution  of  aniline 
or  of  one  of  its  salts,  bromine-water  gives  a  precipitate  of  tri- 
bromoaniline. 

5.  Bleaching-powder  Test  for  Aniline. — A  few  drops  of  ani- 
line are  agitated  with  water,  and  the  solution  separated  from 
undissolved  amine  by  passing  it  through  a  moist  filter.     A 
small  quantity  of  a  clear  solution  of  bleaching-powder  gives 
a  deep-violet  coloration  with  the  filtrate. 

6.  Potassium-dichromate    Test  for   Aniline. — 2  or  3  drops  of 
aniline  are  dissolved  in  dilute  sulphuric  acid.     On  addition 
of   potassium-dichromate  solution,  a  precipitate — green,  blue, 
or   black   according  to  the  concentration — is  obtained.     The 
black  precipitate  is  called  aniline-black. 

7.  Acetoanilide. — A  mixture  of  9  c.c.  of  aniline   and  a  like 
volume  of  glacial  acetic  acid  is  boiled  in  a  flask  with  a  reflux- 
condenser  for  several  hours.     On  cooling,  crystals  of  acetoanilide 
("  antifebrine  ")   are  deposited.     When  recrystallized  from  a 
small  quantity  of  alcohol,  they  melt  at  112°. 

8.  Carbylamine-Reaction. — Aniline  can  be  proved  to  be  a 
primary  amine  by  the  carbylamine-reaction  (VII.,  2). 

9.  Diphenylamine. — (M    g.    of   diphenylamine   is   dissolved 
in  a  small  quantity  of  alcohol,  and  water  is  carefully  added 
until  the  liquid  has  become  very  turbid.     The  amine  is  now 
suspended  in  the  liquid  in  a  fine  state  of  division,  and  can 
be  dissolved  by  addition  of  concentrated  hydrochloric  acid 


xxvii.]  MONOAMINO-COMPOUNDS  55 

drop  by  drop.  On  dilution  of  this  solution  with  water,  the 
diphenylamine  is  reprecipitated,  the  hydrochloride  undergoing 
hydrolytic  dissociation. 

10.  Nitrosodimethylaniline. — 1-4  g.    of   sodium   nitrite  dis- 
solved in  water  is  added  gradually  to  a  well-cooled  solution  of 
2-4  g.  of  dimethylaniline  in  12-5  g.  of  twenty  per  cent,  hydro- 
chloric acid.     Yellow  nitrosodimethylaniline  hydrochloride  is 
precipitated.     It  is  collected  on  a  filter,  washed  with  dilute 
hydrochloric  acid,   and  purified  by  crystallization  from  hot 
water.     The  salt  is  triturated  with  water,  sodium  hydroxide 
is  added,   and  the  green  nitrosodimethylaniline  liberated  is 
dissolved  in  ether.     On  distilling  the  ether,  the  base  is  obtained 
in   splendid,  yellowish-green  leaves.     The  crystals  are  boiled 
with   sodium   hydroxide,   whereby   dimethylamine  is  evolved, 
and  the  liquid  becomes  dark-red  owing  to  the  formation  of 
sodium  nitrosophenoxide.     The  dimethylamine  can  be  identified 
by  its  characteristic  odour,  and  its  alkaline  reaction  to  litmus. 

11.  LlEBERMANN'S  Test  for  Aromatic  Nitroso-compounds. — 
A  few  drops  of  concentrated  sulphuric  acid  are  added  to  a 
solution  of  0*5  g.  of  nitrosodimethylaniline  in  phenol.     After 
slight  heating,  the  mixture  is  poured  into  water.     Addition 
of  sodium  hydroxide  produces  a  fine  dark-blue  colour. 

12.  Azobenzene,  Hydrazobenzene,  and  Benzidine  Sulphate. — 
— A  mixture  of  2  c.c.  of  nitrobenzene  and  20  c.c.  of  twenty 
per  cent,  alcoholic  potash  is  gently  warmed,  and  small  quan- 
tities of  zinc-dust  added.     In  consequence  of  the  formation 
of  azobenzene,  the  liquid  develops  a  red  colour.     On  addition  of 
more  zinc-dust,  the  colour  is  discharged,  and  hydrazobenzene 
produced.     When   the   liquid   is   poured   into   a   quantity   of 
dilute  sulphuric  acid  sufficient  to  make  it  strongly  acid,  nearly 
insoluble  benzidine  sulphate  is  soon  precipitated. 

13.  Diphenylurea. — 1  g.  of  urea    and  3  g.  of  aniline    are 
heated  in  a  test-tube  to  ebullition,  and  the  evolution  of  ammonia 
proved  by  means  of  litmus-paper.     When  the  reaction-mixture 
is  cooled  by  pouring  it  into  a  dish,  crystallization  of  diphenyl- 


56  LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [xxvm. 

urea  causes  solidification.  After  elimination  of  excess  of 
aniline  by  means  of  dilute  hydrochloric  acid,  the  residue  is 
washed  with  water,  and  recrystallized  from  alcohol.  The 
melting-point  of  the  product  should  be  235°. 

XXVIII.     DIAZO-COMPOUNDS   AND    HYDRAZINES. 
(305-310.) 

1.  Benzenediazonium  Chloride. — 9-3  g.  of  aniline  are  dis- 
solved  in  about  100  c.c.  of  hydrochloric  acid  containing  9-2 
g.  of  HC1.     To  this  solution,  maintained  between  5°  and  10° 
by  the  introduction  of  ice,  is  added  very  slowly  a  concentrated 
aqueous  solution  of  7-2  g.  of  commercial  sodium  nitrite,  the 
liquid    being  stirred  constantly.     The  solution  of  benzenedi- 
azonium  chloride  thus  obtained  is  kept  in  a  vessel  surrounded 
by  ice,  and  used  for  experiments  2,  3  and  4. 

2.  Replacement  of  N2-Group  in  Benzenediazonium  Chloride 
by   Hydroxyl. — A  small  quantity  of  the    solution  of  benzene- 
diazonium    chloride  is  warmed  in  a  fractionating  -flask  con- 
nected with  a  condenser.     When  the  evolution  of  nitrogen 
has  ceased  the  solution  is  distilled,  water  and  phenol  passing 
over.     The  latter  can  be  identified  by  its  odour,  and  by  reac- 
tions XXVI.,  4  and  5. 

3.  GATTERMANN'S  Reaction. — A  paste  of  finely -divided  cop- 
per, obtained  by  sieving  zinc -dust  into  a  dilute  solution  of  copper 
sulphate,  is  added  to  a  portion  of  the  solution  of  benzenediazon- 
ium  chloride.     Nitrogen  is  at  once  evolved  with  effervesence. 
On  distilling  the  liquid  with  steam,  chlorobenzene  collects  in 
the  receiver. 

4.  Diazoaminobenzene. — Aniline  is  mixed  with  ten  times  its 
volume  of  water,  and  enough  hydrochloric  acid  to  give  a  clear 

.  solution.  Addition  of  part  of  the  solution  of  benzenediazonium 
chloride  prepared  in  i  and  solid  sodium  acetate  produces  a 
yellow  or  brown  precipitate  of  diazoaminobenzene. 

5.  Aminoazobenzene. — A    small    quantity    of    diazoamino- 
benzene is  warmed  gently  with  about  twice  its  volume  of 


xxix.]  BENZOIC  ACID  AND  ITS  DERIVATIVES  57 

aniline  and  some  solid  aniline  hydrochloride.  Aminoazobenzene 
is  formed.  On  addition  of  concentrated  hydrochloric  acid  and 
solid  salt,  steel-blue  needles  of  aminoazobenzene  hydrochloride 
are  obtained. 

6.  Oxidation  of  Phenylhydrazine  by  FEHLING'S  Solution. — 
A  drop  of  phenylhydrazine  on  a  watch-glass  is  mixed  with 
a  small  quantity  of  concentrated  hydrochloric  acid,  phenyl- 
hydrazine hydrochloride,  nearly  insoluble  in  dilute  hydro- 
chloric acid,  being  formed.  After  pouring  off  the  excess  of 
hydrochloric  acid,  a  small  quantity  of  the  salt  is  dissolved  in 
water  in  a  test-tube,  and  FEHLING'S  solution  (XVI.,  6)  added. 
Reduction  takes  place  at  ordinary  temperature,  with  formation 
of  cuprous  oxide,  Cu20. 

XXIX.     BENZOIC  ACID  AND   ITS   DERIVATIVES. 
(311-313.) 

1.  Benzonitrile    and    Benzoi'c  Acid. — 10  g.  of  sodium  ben- 
zenesulphonate  are  mixed  with  a  like  weight  of  dried  potassium 
ferrocyanide,  and  the  mixture  submitted  to  dry  distillation  in  a 
retort  connected  with  a  condenser.     Benzonitrile  and  a  trace 
of  phenylcarbylamine  distil.     The  ^sonitrile  is  decomposed  by 
warming  with  two  drops  of  concentrated  hydrochloric  acid. 
About  20  c.c.  of  ten  per  cent,  potassium  hydroxide  are  added, 
and  the  mixture  is  boiled  in  a  flask  with  a  reflux-condenser. 
Ammonia  is  evolved,  as  can  be  proved  by  red  litmus-paper, 
while  the  oily  layer  of  benzonitrile  disappears.     The  flask  is 
cooled,    and    concentrated    hydrochloric    acid    added    slowly; 
a  white,  flocculent  precipitate  of  benzoic  acid  is  deposited. 

2.  Benzoic    Acid     from    Gum-benzoin. — a)  5   g.    of  finely- 
powdered  gum-benzoin  are  mixed  with  sand,  and  heated  very 
gently  in  a  porcelain  dish  on  a  sand-bath,  care  being  taken  to 
avoid  fusion.     The  dish  is  covered  with  a  hollow  paper-cone, 
into  which  the  benzoic  acid  sublimes. 

6)  5  g.  of  gum-benzoin  are  boiled  with  milk  of  lime,  the 
alkaline  solution  filtered,  and  hydrochloric  acid  added.  Benzoic 
acid  is  precipitated. 


58    LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY    [xxix. 

3.  Volatility   of  Benzole  Acid   with  Steam. — 1  g.  of  benzole 
acid  is  heated  with  water  in  a  fractionating-flask  connected 
with   a   condenser.     The    acid   volatilizes   with    the   steam, 
and  condenses  as  a  white,  flocculent  precipitate,  the  distillate 
having  an  acid  reaction. 

4.  Solubility   of   Benzoic  Acid   in   Water. — 1  g.   of  benzole 
acid  is  heated  gently  in  a  test-tube  with  1  c.c.  of  water.     At 
first,  two  liquid  layers  are  formed,  and  complete  solution  of 
the  acid  is  only  attained  by  boiling  with  a  large  excess  of  water. 
On    cooling,  it  crystallizes  in  leaflets. 

5.  Ethyl  Benzoate. — 1  g.  of  benzole  acid  is  warmed  with  5 
c.c.  of  absolute  alcohol  and  a  few  drops  of  concentrated  sul- 
phuric acid.     The  ethyl  benzoate  formed  is  characterized  by  a 
peppermint-like  odour. 

6.  Benzanilide. — A   few    cubic    centimetres    of   water    are 
added  to  1  c.c.   of  aniline,  and  then  alternately  small  quanti- 
ties of  potassium  hydroxide  and  benzoyl  chloride  drop  by  drop. 
The  mixture  is  agitated  constantly,  care  being  taken  to  maintain 
it  alkaline.     Finally,  the  alkaline  liquid  is  agitated  till  the 
odour  of  benzoyl  chloride  is  no  longer  perceptible.     The  white 
precipitate  of  benzanilide  is  collected  on  a  filter,  washed  with 
water  till  the  filtrate  is  no  longer  alkaline,  and  crystallized 
from  alcohol.     M.  P.  158°. 

7.  Benzamide. — 3  g.  of  ammonium  carbonate  are  reduced 
to  fine  powder  in  a  mortar,  and  benzoyl  chloride  added  drop 
by  drop,  the  mixture  being  stirred  continuously  with  the  pes- 
tle till  the  odour  of  benzoyl  chloride  is  no  longer  perceptible. 
It  is  lixiviated  with  cold  water  to  remove  ammonium  chloride 
and  carbonate,  and  the  residue  dissolved  in  a  small  quantity 
of  hot  water.     On  cooling,  benzamide  crystallizes  out.     M.  P. 
128°. 

This  substance  is  identified  by  warming  with  dilute  potas- 
sium hydroxide.  Ammonia  is  evolved,  and  addition  of  hydro- 
chloric acid  to  the  alkaline  solution  precipitates  benzole  acid. 


xxx.]  BENZALDEHYDE  59 

XXX.    BENZALDEHYDE. 
(314  and  315.) 

1.  Silver-mirror  Test. — 2  drops  of  benzaldehyde  are  added 
to  an  ammoniacal   solution  of  silver   nitrate,  prepared  as  de- 
scribed in  X.,  2.     Gentle  heating  in  a  water -bath  produces  a 
silver  mirror. 

2.  Benzaldehydephenylhydrazone. — A    few    drops    of   benz- 
aldehyde are  added  to  a  solution  of  phenylhydrazine  in  sul- 
phurous acid.     Benzaldehydephenylhydrazone  is  precipitated, 
and  by  crystallization  from  alcohol  is  obtained  in  large,  fine 
crystals,  melting  at  152°. 

3.  Sulphite    Compound    of   Benzaldehyde. — A    cubic    centi- 
metre of  benzaldehyde  is  agitated  with  a  very  concentrated 
solution  of  sodium  hydrogen  sulphite.     The  crystalline  sul- 
phite compound  is  precipitated,  and  the  odour  of  benzaldehyde 
ceases  to  be  perceptible.     On  warming  with  water,  the  sul- 
phite derivative  is  decomposed,  and  the  benzaldehyde  liberated. 

4.  Action  of  Alcoholic  Potash  on  Benzaldehyde. — On   mix- 
ing 1  c.c.  of  benzaldehyde  with  5  c.c.  of  a  ten  per  cent,  solu- 
tion of  alcoholic  potash,   heat  is  developed,   and  the  liquid 
solidifies  owing  to  the  precipitation  of  potassium  benzoate. 
The  crystals  are  collected  on  a  filter,  washed  with  a  small 
quantity   of  alcohol,   and    dissolved  in  water.     Addition  of 
hydrochloric   acid   precipitates   benzole   acid.     The   alcoholic 
filtrate  contains  benzyl  alcohol  (325). 

5.  Oxidation    of    Benzaldehyde. — a)    By    the    Air. — A   few 
drops  of  benzaldehyde  are  placed  upon  a  glass  plate,  and  allowed 
to  spread.     On  the  following  day,  the  aldehyde  will  be  found 
to  have  changed  completely  into  crystals  of  benzole  acid. 

6)  By  Potassium  Permanganate. — A  few  drops  of  benz- 
aldehyde are  heated  with  an  aqueous  solution  of  potassium 
permanganate.  Manganese  dioxide  is  precipitated,  the  aide- 


60     LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [xxxi. 

hyde  being  oxidized  to  benzole  acid,  which  remains  dissolved 
as  potassium  benzoate.  When  the  odour  of  benzaldehyde  is 
no  longer  perceptible,  two  drops  of  alcohol  are  added  to  reduce 
the  excess  of  potassium  permanganate,  and  the  colourless 
liquid  filtered.  On  acidifying  the  filtrate,  benzole  acid  is 
precipitated. 


XXXI.    BENZENE     HOMOLOGUES     WITH     SUBSTITUTED 
SIDE-CHAINS. 

(321-325.) 

1.  Saponification  of  Benzyl  Chloride  by  Potassium  or  Sodium 
Hydroxide. — 1  c.c.  of  benzyl  chloride    is  warmed  for  a  short 
time  with  10  c.c.  of  ten  per  cent,  alcoholic  potash  or  soda, 
and  the  mixture  diluted  with  a  large  excess  of  water.     If  the 
heating  has  been  of  sufficient  duration,  no  benzyl  chloride 
separates.     After    acidifying    with    nitric    acid,    the    solution 
gives  with  silver  nitrate  a  heavy  precipitate  of  silver  chloride. 

2.  Benzyl    Iodide. — A  small  quantity  of  benzyl  chloride  is 
heated  with  an  alcoholic  solution  of  potassium  iodide  in  a  fume- 
cupboard.     Benzyl  iodide  is  formed,  and  gives  off  an  extremely 
irritating  odour,  productive  of  tears. 

3.  Action  of  Light    on  Toluene  in  Presence  of   Bromine.— 
10  c.c.  of  toluene  are  poured  into  a  test-tube,  and  a  few  drops 
of  bromine  added.     In  daylight,  near  a  window,  the  mixture 
becomes    decolorized  in  a  few  minutes,  gaseous  hydrobromic 
acid  being  evolved. 

4.  Resinification  of  Benzyl  Alcohol. — Concentrated  sulphuric 
acid  is  added  to  a  few  drops  of  benzyl  alcohol.     An  ester  is 
not  formed,  but  the  alcohol  becomes  resinified. 


xxxm.]      POLYSUBSTITUTED  BENZENE  DERIVATIVES       61 


XXXII.    COMPOUNDS    CONTAINING    AN    UNSATURATED 
SIDE-CHAIN. 

(328.) 

i.  Oxidation  of  Cinnamic  Acid  by  Potassium  Permanganate. — 

0-1  g.  of  cinnamic  acid  is  agitated  with  water,  and  several 
drops  of  a  one  per  cent,  solution  of  potassium  permanganate 
added.  The  colour  of  the  solution  is  discharged,  a  precipitate 
of  hydrated  manganese  dioxide  formed,  and  the  liquid  acquires 
an  odour  of  benzaldehyde. 

XXXIII.     POLYSUBSTITUTED   BENZENE  DERIVATIVES. 

(329-350.) 

1.  Reactivity  of  the   Halogen  Atom  in   Halogen   Nitro-com- 
pounds. — 0-1  g.  of  picryl  chloride  is  boiled  with  water  for  a 
few  minutes.     After  acidification  with  nitric  acid,  the  presence 
of  chlorion    is  detected   by  addition    of  a  solution    of  silver 
nitrate. 

2.  ra-Dinitrobenzene. — 1-5  c.c.  of  benzene  are  added  drop 
by  drop  to  a  mixture  of  5  c.c.  of  concentrated  sulphuric  acid 
and  5  c.c.  of  fuming  nitric  acid,  the  liquid  being  agitated  thor- 
oughly during  the  process.     The  solution  is  heated  for  a  few 
minutes,  allowed  to  cool,  and  poured  into  water.     m-Dinitro- 
benzene  is  precipitated,  and  is  freed  from  a  small  percentage 
of  the  ortho-compound  and  traces  of  the  para-compound  by 
crystallization  from  alcohol.     M.  P.  90°. 

3.  Reactivity  of  One  Nitro-group  in  i  :3:5-Trinitrobenzene. — 
0-1  g.  of  l:3:5-trinitrobenzene  is  dissolved  in  boiling  methyl 
alcohol,   and  a  few  drops  of  sodium-methoxide  solution  are 
added.     The    liquid    immediately    becomes    blood-red,    and, 
after  an  interval,  long  colourless  needles  of  3:5-dinitroanisole 
separate. 


62  LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [xxxm. 

4.  Nitrophenols. — 3    c.c.   of    phenol,   liquefied  by  addition 
of  a  small  quantity  of  water,  are  added  slowly  to  18  c.c.  of 
nitric  acid  of  1-17  specific  gravity.     During  the  process,  the 
mixture  is  cooled,  and  agitated  vigorously.     A  heavy,  black 
oil  separates  from  the  aqueous  liquid.     After  washing  with 
water  in  a  small  separating-funnel,  the  oil  is  distilled  with 
steam  (III.,  2).     o-Nitrophenol  distils,  and  can  be    identified 
by  its  odour,  and  by  its  yellow  crystals  melting  at  44°.     The 
residue  in  the  flask  contains  p-nitrophenol. 

5.  Coloured    Salts    of    p-Nitrophenol. — 0-1   g.   of  colourless 
p-nitrophenol    is    dissolved    in    a   dilute    solution    of   sodium 
hydroxide.     The  liquid  has  an  intense  yellow  colour. 

6.  Picric   Acid. — On  carefully  heating  0-1  g.  of  picric  acid 
in  a  test-tube,  the  acid  melts  and  sublimes;  more  rapid  heating 
causes  explosive  decomposition,  leaving  a  residue  of  carbon. 
At  the  same  time,  an  odour  resembling  that  of  nitrobenzene 
becomes  perceptible. 

7.  Potassium     Picrate. — Potassium-hydroxide    solution     is 
added  to  an  alcoholic  solution  of  0-5  g.  of  picric  acid.     Bright- 
yellow  potassium  picrate  is  precipitated,  collected  on  a  filter- 
paper,  and  dried  by  exposure   to   the    air.     The   dry   salt  is 
exploded    by   percussion,    and   by  heating  on  a  platinum  or 
porcelain  crucible-lid.     Only  a  very  minute  quantity  of  the  salt 
must  be  used  for  this  experiment. 

8.  Taste  of  Picric  Acid. — 0-1  g.  of  picric  acid  is  dissolved  in 
water;  the  solution  thus  obtained  has  a  very  bitter  taste. 

9.  Dyeing    with    Picric    Acid. — A  woollen  thread  immersed 
in  the  liquid  is  soon  dyed  bright-yellow. 

10.  ^soPurpuric    Acid. — An  aqueous   solution  of  potassium 
cyanide  is  added  to  one  of  picric  acid.     A  purple  coloration, 
due  to  the  formation  of  the  potassium  salt  of  zsopurpuric  acid, 
is  produced. 

11.  Chloropicrin. — O5  g.  of  picric  acid  is  warmed  carefully 
with  a  solution  of  bleaching-powder.     The  pungent  odour  of 
chloropicrin,  CClsNC^,  becomes  perceptible. 


XXXIIL]      POLYSUBSTITUTED  BENZENE  DERIVATIVES       63 

12.  lonization    of    Picric    Acid    in    Aqueous    Solution. — On 

warming  a  small  quantity  of  picric  acid  with  light  petroleum 
in  a  test-tube,  a  colourless  solution  is  obtained,  the  acid  not 
being  ionized  in  this  solvent.  When,  however,  this  colourless 
solution  is  agitated  with  a  small  quantity  of  water,  the  latter 
acquires  the  deep-yellow  colour  characteristic  of  the  anion  of 
picric  acid. 

13.  Tests    for    Catechol,    Resorcinol,    and    Quinol. — With  a 
drop  of  ferric  chloride,  aqueous  solutions  of  catechol  and  resor- 
cinol  give  a  green  and  a  deep-violet  coloration  respectively. 
With  bromine-water,  resorcinol  yields  a  precipitate  of  tribromo- 
resorcinol. 

Solutions  of  catechol  and  resorcinol  are  made  alkaline  with 
sodium  hydroxide.  They  acquire  a  dark  colour  immediately. 

Addition  of  ammonium  hydroxide  to  a  solution  of  quinol 
turns  it  red-brown. 

14.  Reducing  Power  of  the  Dihydroxybenzenes. — At  ordinary 
temperature,  solutions  of  catechol  and  quinol  reduce  a  solu- 
tion of  silver  nitrate,  with  precipitation  of  metallic  silver  as 
a  black  powder.     Quinol  also  reduces  FEHLING'S  solution. 

15.  Pyrogallol. — On   carefully  heating   5   g.   of  well-dried 
gallic  acid  in  a  retort,  carbon  dioxide — which  can  be  identified 
by  the  lime-water  test — is  evolved,  and  pyrogallol  sublimes. 
The   latter  is   dissolved  in  water,  and    the   solution  divided 
into  three  parts. 

When  silver-nitrate  solution  is  added  to  one,  metallic 
silver  is  precipitated. 

Addition  of  a  drop  of  ferric  chloride  to  the  second  produces 
an  intense  bluish-black  coloration. 

The  third  portion  is  transferred  to  a  thick-walled  test-tube, 
potassium  hydroxide  added,  the  tube  closed  with  a  closely- 
fitting  cork  or  rubber-stopper,  and  the  mixture  vigorously 
agitated.  The  oxygen  in  the  tube  is  absorbed,  the  pyrogallol- 
solution  turning  brown.  On  removing  the  stopper  under 
water,  the  latter  rises  in  the  tube. 


64  LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [xxxm. 

1 6.  Benzoquinone. — A     small     quantity      of     potassium- 
dichromate   solution   and   a   drop   of   concentrated   sulphuric 
acid  are  added  to  a  drop  of  aniline  in  a  dish.     The  pungent 
odour  of  benzoquinone  is  perceived. 

17.  Quinhydrone. — A  solution    of  ferric    chloride  is  added 
to  an  aqueous  solution  of  quinol.     After  an  interval  of  time, 
quinhydrone  crystals  of  beautiful  metallic  lustre  separate. 

18.  Difference  in  Basicity  of  the  Three  Nitroanilines. — 0-5  g. 
of  o-nitroaniline,  w-nitroaniline,  and  p-nitroaniline  respectively 
are   dissolved  in  about   the   same   quantity  of   concentrated 
sulphuric  acid,  and  the  solutions  poured  into  about  100  c.c.  of 
water.     o-Nitroaniline  separates  almost  completely,  indicating 
a  high    degree    of   hydrolysis;    p-nitroaniline   gives   a   yellow 
colour,  due   to   slight  hydrolysis;   the  solution   of  ra-nitroani- 
line  is  colourless,  owing  to  absence  of  hydrolysis. 

19.  Reactivity    of   the    Amino-group   in   Picramide. — 0*1    g. 
of  picramide   is  warmed   with   a   dilute    solution   of  sodium 
hydroxide.     The  formation  of  ammonia  is  proved  by  testing 
with  a  moistened  strip  of  red  litmus-paper. 

20.  p-Diazobenzenesulphonic   Acid. — 1-7  g.  of    sulphanilic 
acid,  NH^-CeH/t-SCbOH  (1  :  4),  are  dissolved  by  heating  with 
25  c.c.  of  two  per  cent,  sodium  hydroxide.     A  concentrated 
aqueous  solution  of  1  g.  of  sodium  nitrite  is  added,  and  the 
mixture   poured   into   excess   of  cold,    dilute   sulphuric   acid. 
After  an  interval,  p-diazobenzenesulphonic  acid  is  precipitated 
as  a  sand-like,  crystalline  powder. 

21.  Oxidation   of  Aminophenols. — 0-1  g.  of   p-aminophenol 
hydrochloride  is  dissolved  in  water,  and  a  solution  of  sodium 
hydroxide  added.     Owing  to  atmospheric  oxidation,  the  liquid 
rapidly  becomes  brown  in  colour. 

22.  Test    for    Nitrous    Acid    with     ?7?-Phenylenediamine.— 
A  drop  of  a  solution  of  sodium  nitrite  and  a  drop  of  dilute 
sulphuric  acid  are   added  to  10  c.c.  of  a  dilute  solution  of 
m-phenylenediamine.     The  liquid  becomes  brown,  Bismarck- 
brown  or  vesuvine  being  formed. 


xxxm.]      POLYSUBSTITUTED  BENZENE  DERIVATIVES      65 

23.  Dyeing   with   Aminoazobenzene. — An  alcoholic  solution 
of  aminoazobenzene  is  diluted  with  water,  and  a  few  drops  of 
dilute  hydrochloric  acid  added.     A  woollen  thread  immersed 
in  the  liquid  for  a  quarter  of  an  hour  is  dyed  yellow,  and  the 
colour  cannot  be  removed  by  washing  with  water. 

24.  Reduction    of   Aminoazobenzene. — A   small  quantity  of 
aminoazobenzene  hydrochloride  is  brought  into  contact  with 
tin    and    hydrochloric    acid.     It    is    decolorized,    yielding    p- 
phenylenediamine  and  aniline.     The  mixture  is  made  strongly 
alkaline  with  sodium  hydroxide,  and  distilled,  using  a  condenser. 
The  presence  of  aniline  in  the  distillate  can  be  proved  by  the 
bleaching-powder  test  (XXVII.,  5). 

25.  Taste    of    "Saccharin." — 0-1    g.    of    "saccharin"    is 
dissolved  in  1  litre  of  water,  and  30  g.  of  sucrose  are  dissolved 
in  a  similar  volume.     When  tasted,  both  solutions  are  found 
to  have  nearly  the  same  degree  of  sweetness. 

26.  Salicylic   Acid. — 0-5  g.  of  salicylic  acid  is  heated  gently 
in  a  test-tube;  it  melts,  and  sublimes.     On  heating  to  a  higher 
temperature,  it  decomposes  partly  into  carbon  dioxide  and 
phenol,  the  characteristic  odour  of  the  latter  becoming  per- 
ceptible. 

27.  Action   of   Bromine-water   on   Salicylic  Acid. — Bromine- 
water  added  to  a  saturated  solution  of  salicylic  acid  gives  a 
precipitate  of  the  formula  C6H2Br3*OBr. 

28.  Identification    of    Salicylic    Acid    and    Phenol. — Ferric 
chloride  is  added  to  alcoholic  and  aqueous  solutions  of  salicylic 
acid  and  phenol  respectively.     Salicylic  acid  gives  the  violet 
coloration  in  both  solvents,  phenol  only  in  water. 

29.  Calcium  Salicylate. — 0-5  g.  of  salicylic  acid  is  added  to  a 
mixture  of  calcium-chloride  solution  and  ammonium  hydroxide. 
On  heating,  calcium  salicylate,  CyH-tOsCajH^O,  is  precipitated. 

30.  Manufacture   of   Ink. — 1  g.  of  gallic  acid  is  dissolved 
in  water,  and  a  solution  of  ferrous  sulphate  added.     When 
employed  as  an  ink,  this  liquid  leaves  a  very  faint  mark  on  the 
paper,  but  on  drying  the  writing  becomes  black. 


66  LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [xxxm. 

31.  Action   of  Tannin    on  Gelatin. — A  solution  of  tannin  is 
added  to  one  of  gelatin.     The  gelatin  is  precipitated. 

32.  Test  for  Tannin. — A  dilute  solution  of  tannin  is  turned 
dark-violet  by  a  drop  of  ferric  chloride.     A  piece  of  oak-bark 
or  cinchona-bark,   an  unroasted   coffee-bean,   and  part  of  a 
gall-nut  are  extracted  with  boiling  water  in  different  dishes. 
The  presence  of  tannin  in  all  these  solutions  can  be  proved  by 
the  ferric-chloride  test. 

33.  Action  of  Tannin  on  Quinine. — On  addition  of  a  solution 
of  tannin  to  one  of  quinine  hydrochloride,  the  alkaloid  is  pre- 
cipitated. 

34.  Interaction  of  Proteins  and  Tannin. — 10  c.c.  of  milk  are 
freed  from  casein  and  fat  by  the  method  described  in  XVIII., 
17.     The  presence  of  proteins  in  the  nitrate  can  be  proved  by 
adding  tannin,   an  insoluble  compound  of  the  proteins  and 
tannin  being  precipitated. 

35.  Decomposition    of    Anthranilic    Acid.  —  0-2    g.    of    dry 
anthranilic  acid  is  heated  in  a  test-tube.     Part  of  it  sublimes, 
and  part  decomposes  with  evolution  of  carbon  dioxide,  and 
formation  of  oily  drops  of  aniline. 

36.  Phthalic   Anhydride. — 0*1  g.  of  phthalic  acid  is  heated 
in  a  dish,  covered  with  a  watch-glass,  on  a  sand-bath.     Long 
needles  of  phthalic  anhydride  sublime. 

37.  Fhioresce'in. — Some  crystals  of  phthalic  anhydride  and  a 
like  quantity  of  resorcinol  are  heated  for  a  few  minutes  with  1  c.c. 
of  concentrated  sulphuric  acid.     To  prevent  the  liquid  becoming 
dark-coloured,  the  heating  must  not  be  too  prolonged,  or  the 
temperature  too  high.     On  dissolving  the  mixture  in  100  c.c.  of 
water  and  adding  sodium  hydroxide,  a  beautifully  fluorescent, 
yellowish-green  solution  containing  fluorescein  is  obtained. 

38.  Phenolphthalein. — A    mixture    of    like    quantities    of 
phthalic  anhydride  and  phenol  is  wrarmed  with  concentrated 
sulphuric  acid,  phenolphthalein  being  formed.     When  this  is 
added  to  a  dilute  solution  of  a  caustic  alkali,  a  red  coloration 
is  produced. 


xxxiv.]  HYDEOCYCLIC  COMPOUNDS  67 

39.  Red  Anion  of  Phenolphthalein. — A  few  milligrammes  of 
phenolphthalem  are  dissolved  in  absolute  alcohol  containing  a 
trace  of  calcium  hydroxide  in  suspension;  the  liquid  remains 
colourless.  On  dilution  with  water,  the  calcium  compound  of 
the  phthalei'n  is  ionized,  with  production  of  a  red  colour 


XXXIV.    HYDROCYCLIC   COMPOUNDS. 
(365-370.) 

1.  Artificial  Camphor. — American  or  German  oil  of  turpen- 
tine is  dried  by  calcium  chloride,  poured  off,  and  distilled. 
Being  turbid,   the  first  few  cubic   centimetres  of  the  distil- 
late are  rejected.     Dry  hydrochloric-acid  gas,  prepared  by  the 
method  of  IX.,  15,  is  led  into  10  c.c.  of  the  dry,  quite  clear 
turpentine,  the  flask  being  cooled  by  ice.     After  some  time, 
transparent    crystals    of   pinene    hydrochloride  or  "  artificial 
camphor/7  CioHi6,HCl,  are  deposited.     The  mother-liquor  is 
poured  off,  and  the  crystals  dried  by  pressing  between  layers 
of  filter-paper.     In  odour  and  appearance  pinene  hydrochloride 
resembles  camphor. 

2.  Volatility  of  Camphor  with  Steam. — A  piece  of  camphor 
is  placed  in  water  in   a  fractionating-flask  connected  with  a 
condenser.     On  heating,  the  camphor  passes  over  with  the 
steam. 

3.  Camphor  and  Water. — A  piece  of  camphor  thrown  upon 
the  surface  of  water  acquires  a  rotatory  motion,  due  tov  dis- 
parity of  the  vapour-tension  for  the  different  crystal  faces. 

4.  Camphoric  Acid. — 2  g.  of  camphor  arc  heated  in  a  flask 
with  dilute  nitric  acid  for  some  minutes,  and  evaporated  almost 
to  dry  ness  in  a  porcelain  dish.     The  residue  is  diluted  with 
water,  made  alkaline  with  sodium  hydroxide,  and  the  undis- 
solved  portion  filtered  off.     If  the  filtrate  is  not  too  dilute, 
hydrochloric  acid  precipitates  camphoric  acid. 


68    LABORATOEY  MANUAL  OF  ORGANIC  CHEMISTRY  [xxxv. 


XXXV.    BENZENE-NUCLEI  LINKED  TOGETHER  BY 
CARBON. 

(371-374.) 

1.  Rosolic     Acid. — A  mixture  of  2  c.c.  of  phenol,  0-5  g. 
of  oxalic  acid,  and  5  c.c.  of  concentrated  sulphuric  acid  is 
heated  in  a  test-tube.     It  acquires  a  red  colour.     On  pouring 
the  liquid  into  water,  and  making  it  alkaline  with  potassium 
hydroxide,   a  dark-red    solution   is    obtained,  containing   the 
potassium  salt  of  rosolic  acid. 

2.  Magenta. — 1  c.c.  of  aniline  is  heated  in  a  test-tube  with 
1  g.  of  p-toluidine  and  0*5  g.  of  mercuric  chloride,  magenta 
being  formed.     On  pouring  the  liquid  into  water  containing 
a  small  quantity  of  hydrochloric  acid,  a  deep-red  solution  is 
produced. 

3.  Action  of  Concentrated  Hydrochloric  Acid  on  a  Solution 
of  Magenta. — Concentrated  hydrochloric  acid  is  added  to  part 
of  the  solution  obtained  in  2.     The  liquid  becomes  yellow, 
owing  to  the  formation  of  the  hydrochloride  of  the  rosaniline 
base  containing  3HC1.     When  this  is  poured  into  a  large  quan- 
tity of  water,  the  red  colour  is  restored. 

4.  Colour-base. — Excess  of  solution  of  ammonium  or  potas- 
sium hydroxide  is  added  to  another  portion  of  the  magenta 
solution.     The  colour-base  is  formed,  and  the  liquid  decolorized. 

5.  Leuco-base. — A  third  portion  of  the  magenta  solution  is 
treated  with  zinc  and  hydrochloric  acid,  without  the  applica- 
tion of  heat.     The  leuco-base  is  formed,  and  the  colour  dis- 
charged, 


xxxvi.]  CONDENSED  BENZENE-NUCLEI  69 

XXXVI.    CONDENSED  BENZENE-NUCLEI. 

(377-385.) 

1.  Action  of  Heat  on  Naphthalene. — 0*5  g.  of  naphthalene  is 
heated  in  a  test-tube.     It  melts,  and  sublimes  readily. 

2.  Naphthalene     Picrate. — 3   c.c.   of  a   concentrated  ether 
solution  of  picric  acid  are  mixed  with  a  like  volume  of  a  con- 
centrated solution  of  naphthalene  in  that  solvent.     A  yellow, 
crystalline  precipitate  of  naphthalene  picrate  is  produced. 

3.  Naphthalenemonosulphonic  Acids. — A  mixture  of  0-5  g. 
of  naphthalene  and  2  c.c.  of  concentrated  sulphuric  acid  is 
heated  in  a  test-tube  for  a  few  minutes,  allowed  to  cool,  and 
poured  into  water.     On  treatment  with  barium  carbonate  by 
the  method  of  VI.,  2,  the  presence  of  the  dissolved  sulphonic 
acids  is  proved. 

4.  a-Nitronaphthalene. — 1   g.   of    naphthalene    is   dissolved 
in  5  c.c.  of  concentrated  nitric  acid,  and  the  solution  poured 
into   water.     The   precipitated   yellow   a-nitronaphthalene   is 
crystallized  from  a  small  quantity  of  alcohol,  being  obtained 
in  yellow  needles,  melting  at  61°. 

5.  Crude    Naphthol. — 0-5  g.  of  naphthol  is  agitated  with 
water;     only    a    small    quantity    dissolves.     On    addition    of 
potassium  or  sodium  hydroxide,  a  solution  is  obtained,  from 
which  carbon  dioxide  reprecipitates  the  naphthol. 

6.  Martius's    Yellow. — 1  g.  of  a-naphthol  is  dissolved  in  3 
c.c.  of  concentrated  sulphuric  acid,  and  the  solution  poured  into 
3  c.c.  of  concentrated  nitric  acid.     When  this  mixture  is  diluted 
with  water,  dinitro-a-naphthol  is  precipitated.     It  is  filtered 
off,  washed,  transferred  to  a  vessel  containing  water,  and  dis- 
solved by  addition  of  a  small  quantity  of  sodium  hydroxide, 
with    formation    of    the    sodium    salt,    Martius's    yellow.     A 
woollen  thread  dipped  into  this  solution  becomes  dyed  deep- 
vellow. 


70  LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [xxxvi. 

7.  Naphthylamines. — 0*5     g.    of    a-naphthylamine    is    dis- 
solved in  dilute  hydrochloric  acid.     With  ferric  chloride  this 
solution  gives  a  blue  precipitate.     A  similar  solution  of  pure 
/3-naphthylamine  does  not  react  thus. 

8.  Congo-red. — A  few  centigrammes  of  congo-red  are  placed 
in  water,  and  a  drop  of  concentrated  hydrochloric  acid  added. 
The  liberated  acid  turns  the  liquid  blue;   addition  of  an  alkali 
restores  the  red  colour. 

9.  Naphthionic   Acid. — A   mixture  of  1  g.  of  a-naphthyla- 
mine  and  3  c.c.  of  concentrated  sulphuric  acid  is  heated  in  a 
test-tube  for  a  few  minutes,  and  poured  into  water.     On  mak- 
ing the  liquid  alkaline  with  sodium  hydroxide,  it  exhibits  an 
intense  reddish-blue  fluorescence,  resulting  from  the  formation 
of  sodium  naphthionate. 

10.  Oxidation    of     Anthracene     by    Chromic    Acid. — Small 
quantities  of  an  acetic-acid  solution  of  chromic  acid  are  added 
to  a  solution  of  3  g.  of  anthracene  in  this  solvent,  until  the 
energetic  reaction  has  ceased.     The  liquid  is  poured  into  water, 
and  the  precipitated  anthraquinone  collected  on  a  filter. 

11.  Test   for   Anthraquinone. — A  few  centigrammes  of    an- 
thraquinone  are   heated   in   a  test-tube   with   zinc-dust   and 
sodium  hydroxide,  a  deep  blood-red  solution  of  anthraquinol 
being  formed.     On  agitating  this  solution  with  air,  the  colour 
is  discharged. 

12.  Potassium   Salt   of  Alizarin. — A   few   centigrammes    of 
alizarin  are  placed  in  water,  but  the  substance  does  not  dissolve. 
Cn  addition  of  a  dilute  solution  of  potassium  hydroxide,  the 
very  intense  deep-blue  colour  of  the  potassium  salt  is  developed. 


xxxvii.]  HETEROCYCLIC  COMPOUNDS  71 

XXXVII.    HETEROCYCLIC    COMPOUNDS. 
(387-399.) 

1.  Pyridine. — Some  drops  of  pyridine  are  added  to  a  few 
cubic  centimetres  of  water,   the  base  dissolving  completely. 
The  solution  has  an  alkaline  reaction. 

2.  Action    of    Pyridine    on    Ferric    Chloride. — The  aqueous 
solution  of  pyridine  gives  with  one  of  ferric  chloride  a  precipi- 
tate of  ferric  hydroxide. 

3.  Action  of  Pyridine  on  Mercuric   Chloride. — A  solution  of 
mercuric  chloride  added  to  a  pyridine  solution  precipitates  a 
white,  crystalline  compound  of  pyridine  and  mercuric  chloride. 

4.  Test  for  Pyridine. — Hydrochloroplatinic  acid,  H^PtCle, 
is  added  to  a  small  quantity  of   a  solution  of   pyridine;    no 
precipitate  is  formed.     On  boiling  the  mixture  for  a  short 
time,    a   yellow   powder   of   the   formula   PtCL^CsHsN^   is 
deposited.     This  test  is  characteristic  for  pyridine. 

5c  Action  of  the  Alkaloid-reagents  on  Pyridine. — The  alkaloid- 
reagents  (407) — among  them  tannin,  phosphomolybdic  acid, 
and  picric  acid — precipitate  pyridine  from  solution. 

6.  Stability  of  Pyridine  towards  VON  BAEYER'S  Reagent. — A 
solution  of  potassium  permanganate  and  sodium-  carbonate 
is  added  to  one  of  pyridine.     The  violet-red  colour  is  not 
altered. 

7.  Stability  of  Pyridine  towards  Oxidizing  Agents. — A  solu- 
tion of  pyridine  is  heated  with  sodium  or  potassium  dichromate 
and  concentrated  sulphuric  acid.     The  colour  of  the  solution 
undergoes  no  change. 

8.  Pyrrole-red. — Water  is  added  to    a  small  quantity  of 
"  Dippel's  oil  "  (387)  in  a  test-tube,  and  the  mixture  boiled. 
A  wood-splint  moistened  with  concentrated  hydrochloric  acid 
becomes  coloured  red  by  the  vapour,  pyrrole-red  being  formed. 

9.  Indophenin-reaction. — A  cubic  centimetre  of  crude  ben- 
zene and  a  like  volume  of  concentrated  sulphuric  acid  are 


72  LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [xxxvm. 

brought  into  contact  with  a  fragment  of  isatin.  In  presence 
of  thiophen,  the  layer  of  sulphuric  acid  develops  an  intense 
blue  colour. 

10  c.c.  of  crude  benzene  are  agitated  repeatedly  with  warm, 
concentrated  sulphuric  acid,  about  2  c.c.  being  used  for  each 
operation.  The  benzene  is  separated,  and  tested  by  the  indo- 
phenin-reaction.  Either  the  blue  coloration  is  not  produced, 
or  it  is  much  less  pronounced  than  in  the  first  experiment. 

10.  Tests  for  Antipyrine. — A  solution  of  antipyrine  is 
turned  red  by  ferric  chloride,  bluish-green  by  potassium  or 
sodium  nitrite  and  acetic  acid. 


XXXVIII.    CONDENSATION-PRODUCTS  OF  BENZENE  AND 
HETEROCYCLIC  NUCLEI. 

(400-405.) 

1.  SKRAUP'S  Synthesis  of  Quinoline. — A  mixture  of  4  c.c.  of 
aniline,  12  c.c.  of  glycerol,  2-5  c.c.  of  nitrobenzene,  and  6  c.c. 
of  sulphuric  acid  is  heated  carefully  in  a  flask  till  the  reaction 
begins,  the  burner  being  then  removed.     When  it  has  moder- 
ated, the  heating  is  resumed,  and  continued  for  five  or  ten 
minutes.     The  liquid  is  cooled,  poured  into  water,  and  dis- 
tilled with  steam  (III.,  2)  after  addition  of  excess  of  sodium 
hydroxide.     The  turbidity  of  the  distillate  is  caused  by  the 
presence   of  minute   drops   of  quinoline.     The   characteristic 
odour  of  the  base  is  perceived. 

2.  Quinoline    Hydrochloride. — On  addition  of  hydrochloric 
acid  to  the  distillate  obtained  in  i,  the  liquid  becomes  clear, 
soluble    quinoline    hydrochloride    being    formed.     Sodium    or 
potassium  hydroxide  reprecipitates  the  quinoline  in  oily  drops. 

3.  Quinoline  Picrate. — With  a  solution  of  quinoline  hydro- 
chloride,  a  saturated,  aqueous  solution  of  picric  acid  gives  a 
yellow,  amorphous  precipitate  of  quinoline  picrate. 


xxxix.]  ALKALOIDS  73 

4.  Quinoline   Bichromate. — With  quinoline  salts,  potassium 
dichromate  gives  a  yellow,  crystalline  precipitate  of  quinoline 
dichromate,  (CgHrN^I^C^Or. 

5.  Volatility   of   Indigo. — On  heating  0-1  g.  of  indigo  in  a 
test-tube,  a  violet  vapour  is  formed. 

6.  Solubility   of  Indigo   in   Nitrobenzene. — 0-1  g.  of  indigo 
is  heated  with  a  small  quantity  of  nitrobenzene.     It  dissolves, 
and,  on  cooling,  crystallizes. 

7.  Indigosulphonic  Acid. — 0*1   g.  of  indigo  is  dissolved  in 
1  c.c.  of  fuming  sulphuric  acid.     Indigosulphonic  acid  is  formed, 
so  that  the  indigo  is  not   reprecipitated   when  the  solution  is 
poured  into  water. 

8.  Oxidation   of  Indigo  to   Isatin. — The  solution  of  indigo- 
sulphonic  acid  obtained  in  7  is  warmed  with  a  small  quantity  of 
concentrated  nitric  acid.     It  is  decolorized,  and  isatin  formed. 

9.  "Vat-dyeing." — 0-1    g.   of  powdered    indigo    is  heated 
with  a  solution  of  sodium  hyposulphite,  Na2S204  ("  Inorganic 
Chemistry/7   83).     Sodium   thiosulphate,    miscalled    "  sodium 
hyposulphite/7  must  not  be  used.     A  strip  of  linen  or  cotton  is 
immersed  in  the  solution  of  indigo-white,  and  hung  up  to  dry. 
The  oxygen  of   the  atmosphere  oxidizes  the  indigo-white  to 
indigo-blue. 


XXXIX.    ALKALOIDS. 
(406-415.) 

1.  Alkaloid-reagents. — A  solution   of  an   alkaloid,  such  as 
quinine  hydrochloride  or  sulphate,  is  tested  with  solutions  of 
the  ordinary  alkaloid-reagents;   for  example,  tannin,  phospho- 
molybdic  acid,  mercuric  potassium  iodide,  and  a  solution  of 
iodine  in  one  of  potassium  iodide.     With  each  a  precipitate  is 
formed. 

2.  Nicotine. — 10  g.  of  tobacco  are  boiled  with  100  c.c.  of 
water  containing  a  small  quantity  of  sulphuric  acid.     After 


74  LABORATORY  MANUAL  OF  ORGANIC  CHEMISTRY  [xxxix. 

filtering,  the  filtrate  is  rendered  alkaline,  and  distilled.  The 
distillate  contains  nicotine,  and  yields  precipitates  with  plati- 
num chloride,  mercuric  chloride,  and  a  potassium-iodide  solu- 
tion of  iodine. 

3.  Fluorescence    of    Quinine-sulphate     Solution. — 0-1  g.  of 
quinine  sulphate  is  dissolved  in  water  containing  sulphuric  acid. 
The  solution  exhibits  a  blue  fluorescence. 

4.  Action  of  Chlorine  on  Quinine  Salts. — Chlorine-water  is 
added  to  a  solution  of  a  quinine  salt  until  the  liquid  smells 
strongly  of  the  gas.     On  addition  of  ammonium  hydroxide,  an 
emerald-green  coloration  is  produced. 

5.  Test  for  Strychnine. — A  crystal  of   strychnine  nitrate  is 
placed  in  a  porcelain  dish,  and  a  few  drops  of  concentrated  sul- 
phuric acid  added.     A  small  crystal  of  potassium  dichromate 
produces  with  this  liquid  a  very  intense  bluish-violet  colour. 

6.  Test  for  Brucine. — A  small  quantity  of  brucine  yields  a 
red  coloration  with  concentrated  nitric  acid;    on  the  applica- 
tion of  gentle  heat,  the  colour  changes  to  yellow.     Dilution  with 
water,  and  addition  of  ammonium  sulphide  renders  the  yellow 
solution  violet. 


INDEX. 


The  basis  of  the  arrangement  of  this  index  is  threefold: 

(1)  The  numbers  refer  to  pages. 

(2)  In  all  instances  of  possible  ambiguity  as  to  the  identity  of  the  principal 
references,  they  are  given  in  old-style  figures. 

(3)  Where  a  reference  is  a  sub-division  of  a  principal  heading,  it  is  indented 
one  em  space  for  each  word  of  the  principal  heading  not  repeated.     Portions 
of  words  followed  by  a  hyphen  are  treated  as  words  for  the  purposes  of  .this 
arrangement. 


A. 

Acetal,  21. 

Acetaldehyde,  21,  32. 
Acetamide,  2,  12. 
Acetate,  Acetoferric,  18. 

Basic  ferric,  18. 

Calcium,  22. 

Ethyl,  20,  42. 

Lead,  4,  5,  19,  29,  42. 

Potassium,  38. 

Silver,  17. 

Sodium,  7,  17,  18,  56. 
Acetic  acid,  10,  17,  18,  20,  23,  26, 
38,  54. 

Tests  for,  17, 18,  23. 
Acetoanilide,  54. 
Aceto-ferric  acetate,  18. 
Acetone,  22,  23,  34. 

Test  for.  22. 
Acetylene,  24,  25. 

Copper.  24. 

Silver,  24. 

Acid,  Acetic,  10,  17,  18,  20,  23,  26, 
38,  54. 

Amalic,  50. 

Anthranilic,  66. 

Benzenemonosulphonic,  50. 

Benzole,  57,  58,  59,  60. 

n-Butyric,  19. 


Acid,  Camphoric,  67. 
Carbamic,  49. 
Carbolic.     See  phenol. 
Cinnamic,  61. 
Citric,  33,  34. 
Cyanic,  46. 
Cyanuric,  48. 

p-Diazobenzensulphonic,  64. 
Ethylsulphuric,  10,  11. 
Ferrocyanic,  44. 
Formic,  15-17,  27,  32,  34. 
Gallic,  63,  65. 
Glucosesulphuric,  37. 
Glyoxylic,  43. 
Hydrocyanic,  43,  44. 
Indigosulphonic,  73. 
Lactic,  32. 
I'flpvulic,  37. 
Methylnitrolic,  14. 
Mucic,  38,  39. 
Naphthionic,  70. 
Oleic,  25. 

Oxalic,  7,  15, 16,  27,  28-31,  47,  68. 
Phthalic,  66. 

Picric,  53,  62,  63,  69,  71,  72. 
Propionic,  15. 
isoPurpuric,  62. 
Racemic,  33. 
Rosolic,  68. 
Salicylic,  6,  65. 

75 


76 


INDEX 


Acid,  Succinic,  31. 

Sulphanilic,  64. 

Tartaric,  32,  33. 

Uric,  49,  50. 

Xanthic,  47. 
Acids,  CnH2nO2,  Saturated,  15-20. 

Higher  fatty,  19. 

Hydroxy-,  32-34. 

Monobasic  unsaturated,  25,  26. 

Naphthalenemonosulphonic,  69. 

Saturated  dibasic,  28-32. 

Volatile  fatty,  19. 
Acraldehyde,  28. 
ADAMKIEWICZ'S  reaction,  43. 
Albumin,  Egg-,  2-4,  22,  42, 43. 
Albuminate,  Copper,  43. 
Alcohol,  Allyl,  27,  28. 

Benzyl,  59,  60. 

Ethyl,  5,  8-10,   11,   18,  20,  21, 
23,  26,  27,  31,  42,  47,  58. 

Methyl,  22,  29. 

Tests  for  ethyl,  10,  27,  58. 

water  in,  9,  10. 
Alcohols,    Aldehyde-      See   sugars. 

CnH2n+i-OH,8-10. 

Keto-.     See  sugars. 
Aldehyde-resin,  21. 
Aldehydes,  21,  22. 
Aldehy  do-alcohols.     See  sugars. 
Alizarin,  70. 

Potassium  salt  of,  70. 
Alkaloid-reagents,  71,  73. 
Alkaloids,  73,  74. 
Alkyl  halides,  10. 
Allot^ropic  modifications  of  carbon, 

4,5. 

Alloxantine,  49. 
Allyl  alcohol,  27,  28. 
Almond  oil,  25,  26. 
Aluminium  carbide,  7. 
Amalic  acid,  50. 
Amines,  12-14,  53-55. 

Test  for  primary,  12. 

Amino-azobenzene,  65. 

hydrochloride,  65. 

-phenol,  p-,  64. 
Ammonia  copper  cyanurate,  48. 

cyanate,  47. 

dithiocarbamate,  49. 

formate,  44. 

oxalate,  29,  30. 

purpurate,  49. 


Ammonium  thiocyanate,  3,  49. 

urate,  49. 
Amylene,  24. 
Amyloid,  41. 
Analysis     of     carbon     compounds, 

Qualitative,  1-4. 

Aniline,  36,  42,  53,  54,  55,  56,  58, 
64,  66,  72. 

-black,  54. 

hydrochloride,  57. 

Tests  for,  54. 
Anthracene,  70. 
Anthranilic  acid,  66. 
Anthraquinol,  70. 
Anthraquinone,  70. 

Test  for,  70. 

Antifebrine.     See  acetoanilide. 
Antipyrine,  72. 
Artificial  camphor,  67. 
Azobenzene,  55. 


B. 

BAEYER'S  test  for  the  double  bond, 

VON,  24,  25,  50,  71. 
Barium  alkoxide  of  starch,  40. 

ethylsulphate,  11. 

glucosesulphate,  37. 

succinate,  31. 

trithiocarbonate,  47. 
BEILSTEIN'S  test,  3. 
Benzaldehyde,  59,  60. 

-phenylhydrazone,  59. 
Benzamide,  58. 
Benzanilide,  58. 
Benzene,  6,  7,  50,  51,  61,  71,  72. 

-diazonium  chloride,  56. 

-monosulphonic  acid,  50. 

-sulphonate,  Sodium,  50,  52,  57. 
Benzidine  sulphate,  55. 
Benzoate,  Calcium,  51. 

Ethyl,  58. 

Potassium,  59,  60. 
Benzoic  acid,  57,  58,  59,  60. 
Benzonitrile,  57. 
Benzoquinone,  64. 
Benzoyl  chloride,  58. 
Benzyl  alcohol,  59,  60. 

chloride,  60. 

iodide,  60. 
Bismarck-brown,  64. 


INDEX 


77 


Biuret,  48. 

-reaction,  43,  48. 
Boiling-point,  Determination  of,  6, 

7. 

Bone-charcoal,  4,  5 . 
Bran,  36. 
Brucine,  74. 

Test  for,  74. 
BUNSEN,  48. 
Butter,  18,  19. 
Butyric  acid,  n-,  19. 


C. 

Cacodyl  oxide,  17. 

-test,  17. 
Calcium  acetate,  22. 

alkoxide  of  dextrose,  37. 

benzoate,  51. 

carbamate,  49. 

carbide,  24. 

citrate,  34. 

oxalate,  28,  29. 

-oxide  test,  3. 

potassium  ferrocyanide,  44. 

racemate,  33. 

saccharate,  39. 

salicylate,  52,  65. 

tartrate,  33. 
Camphor,  67. 

Artificial,  67. 
Camphoric  acid,  67. 
Cane-sugar.     See  sucrose. 
Caramel,  39. 
Carbamate,  Calcium,  49. 
Carbamic  acid,  49. 
Carbide,  Calcium,  24. 
Carbolic  acid.     See  phenol. 
Carbon,  Allotropic  modifications  of, 
4,  5. 

Detection  of,  1,  2. 

disulphide,  12,  46,  47,  49. 

monoxide,  29. 

tetrachloride,  8. 
Carbonization,  1. 
Carbylamine,  Ethyl-,  15. 

Methyl-,  12. 

-reaction,  12,  54. 
Carbylamines,  12,  15. 
CARIUS'S  test,  3, 


Casein,  38,  66. 
Catechol,  63. 
Cellulose,  41,  42. 

Nitro-,  41,  42. 
Charcoal,  Bone-,  4,  5. 

Wood-,  4. 
Chloral,  34. 

hydrate,  34,  35. 
Chloride,  Benzyl,  60. 
Chlorobenzene,  Mono-,  51,  52,  56. 
Chloroform,  3,  8,  26,  27,  34,  51. 
Chloropicrin,  62. 
Cinchona-bark,  66. 
Cinnamic  acid,  61. 
Citrate,  Calcium,  34. 
Citric  acid,  33,  34. 
Coagulation  of  proteins,  42,  43. 
Coal-gas,  1,  24. 
Coffee-beans,  66. 
Collodion,  42. 

Colour-base  of  magenta,  68. 
Congo-red,  70. 
Copper  acetylene,  24. 

albuminate,  43. 

alkoxide  of  dextrose,  37. 

ammonium  cyanurate,  48. 
oxalate,  30. 

oxalate,  29,  30. 
CRAFTS.     See  FRIEDEL. 
Cresol,  53. 

CRISMER'S  test,  9,  10. 
Crystallization,  7. 
Cupric  xanthate,  47. 
Cuprous  xanthate,  47. 
Cyanate,  Ammonium,  47. 

Potassium,  45,  47. 
Cyanic  acid,  46. 
Cyanide,    Potassium,    27,    44,   45, 

46,  62. 
silver,  44. 

Silver,  44. 

Cyanurate,  Copper  ammonium,  48. 
Cyanuric  acid,  48. 

D. 

Detection  of  carbon,  1, 2. 
halogens,  2,  3. 
hydrogen,  1,  2. 
nitrogen,  2. 
sulphur,  3,  4. 


78 


INDEX 


Dextrin,  40,  41. 
Dextrose,  35,  37, 40,  41. 
Diastase,  40. 
Diazo-aminobenzene,  56. 

-benzenesulphonic  acid,  p-,  64. 

-compounds,  56. 

Dibasic  acids,  Saturated,  28-32. 
Diethyl-amine  hydrochloride,  14. 

-nitrosoamine,  14. 

oxalate,  31. 

Dihydroxy benzenes,  63. 
Dimethyl-amine,  14,  55. 

aniline,  55. 

oxalate,  30. 
Dinitro-anisole,  3  :  5-,  61. 

-benzene,  w-,  61;  o-,  61;  p-t  61. 

-a-naphthol,  69. 
Dioses,  38,  39. 
Diphenyl-amine,  54,  55. 
hydrochloride,  55. 

-urea,  65,  56. 
DIPPEL'S  oil,  71. 
Distillation,  Fractional,  5. 

Steam,  6. 

Dithiocarbamate,  Ammonium,  49. 
Dyeing,  62,  65,  69,  73. 

E. 

Egg-albumin,  2,  3,  22,  42,  43. 

Ela'idic  transformation,  25. 

Eosin,  30. 

Esters,  10, 11, 18-21. 

Ether,  6,  n,  12. 

Ethers,  11,  12. 

Ethoxide,  Sodium,  8,  9,  14. 

Ethyl  acetate,  20,  21,  42. 

alcohol,   5,  8-10,  11,  18,  20,  21, 

23,26,27,31,42,47,58. 
Tests  for,  27,  58. 

-amine  hydrochloride,  13. 

benzoate,  58. 

-carbylamine,  15. 

chloride,  10. 

-mercaptan,  12. 

nitrite,  13. 

-sulphate,  Barium,  11. 
Potassium,  12,  15. 

-sulphuric  acid,  10,  11. 
Ethylene,  23,  24. 

bromide,  24. 
Extraction  with  solvents,  6. 


F. 

Fatty  acids,  Higher,  19. 

Volatile,  19. 
FEELING'S  solution,  33,  35.  38,  39, 

57,  63. 
Ferric  acetate,  Aceto-,  18. 

Basic,  18. 

succinate,  Basic,  31. 
thiocyanate,  46^  49. 
Ferricyanide,  Potassium,  45. 
Ferrocyanic  acid,  44. 
Ferrocyanide,  Potassium,  15,  43,  44, 

45,  57 
calcium,  44. 
Fluorescein,  66. 
Formaldehyde,  22. 
"  Formalin/'  22. 
Formate,  Mercuric,  16. 
Mercurous,  16. 
Potassium,  27,  28. 
Silver,  16. 
Sodium,  29. 

Formic  acid,  15-17,  27,  32,  34. 
Fractional  distillation,  5. 
FRIEDEL    and    CRAFTS'S    reaction. 

51. 

Furfuraldehyde,  36. 
-hydrazone,  36. 
-test,  36. 
Fusel-oil,  9, 


G. 

Galactose,  d-,  38,  39. 
Gallic  acid,  63,  65. 
Gall-nuts,  66. 

GATTERMANN'S  reaction,  56. 
Gelatin,  66. 

Glucosazone,  Phenyl-,  35,  36. 
Glucose-sulphate,  Barium,  37. 

-sulphuric  acid,  37. 
Glycerol,     15,     19,     27,     28,     36, 

72. 

Glycerose,  36. 
Glyceryl  oleate,  25. 
Glyoxylic  acid,  43. 
Graphite,  4. 
Gum-benzoin,  57. 
Guncotton,  42. 


INDEX 


79 


H. 

Halogens,  Detection  of,  2,  3. 
Heterocyclic  compounds,  71,  72. 
Hexodioses,  38,  39. 
Hexoses,  36-38. 

Hydrochloric-acid    test    for,    36, 

37. 

"  Humic  substances,"  37. 
Hydrazines,  57. 
Hydrazobenzene,  55. 
Hydrocarbons,  Saturated,  7,  8. 

Unsaturated,  23-25. 
Hydrocyanic  acid,  43,  44. 
Hydrocyclic  compounds,  67. 
Hydrogen,  Detection  of,  1,  2. 
Hydrolysis  of  nitriles,  15. 
Hydroxy-acids,  32-34. 


I. 

Indigo,  73. 

-sulphonic  acid,  73. 

-vat-dyeing,  73. 
Indophenin-reaction,  71,  72. 
Iodide,  Benzyl,  60. 
lodoform,  27,  34. 

-test,  10,  13,  14,  27. 
Iron  ammonium  tartrate,   32,   33. 
Isatin,  72,  73. 
/sonitriles,  12,  15. 
/sopurpurate,  Potassium,  62. 
/sopurpuric  acid,  62. 

K. 

Keratin,  43. 

Keto-alcohols.     See  sugars. 
Ketones,  22,  23. 
KJELDAHL'S  method,  2. 
KNOP,  48. 

L. 

Laboratory  methods,  5-7. 
Lactic  acid,  32. 
Lactosazone,  39. 
Lactose,  38,  39. 
Lsevulic  acid,  37. 
Lsevulose,  38. 
-test,  38,  39, 


LASSAIGNE'S  test  for  nitrogen,   2, 

27. 
Lead  acetate,  4,  5, 19, 29. 

oleate,  26. 

oxalate,  29. 
"  Lead-plaster,"  26. 
Lemons,  33. 

keuco-base  of  magenta,  68. 
LIEBERMANN'S  test,  55. 
LIEBIG,  48. 
Lignin,  Test  for,  42. 
Linseed  oil,  46. 

M. 

Magenta,  4,  21,  68. 
Malt-extract,  40. 
Martius's  yellow,  69. 
Melting-point,    Determination    of, 

6. 

Mercaptan,  Ethyl-,  12. 
Mercuric  formate,  16. 
Mercurous  formate,  16. 
Methane,  7,  8,  18. 
Methyl  alcohol,  22,  29. 

-amine,  12,  15. 

-carbylamine,  12. 

-mustard-oil,  13. 

-nitrolate,  Sodium,  14. 

-nitrolic  acid,  14. 
Method,  KJELDAHL'S,  2. 
Methods,  Laboratory,  5-7. 
Methoxide,  Sodium,  61. 
Methylene  chloride,  8. 
Milk,  38,  66. 
MILLON'S  reagent,  43. 
Monobasic  unsaturated  acids,   25, 

26. 

Monochlorobenzene,  51,  52,  56. 
Monoses,  35-38. 
Mucate,  Potassium,  38. 
Mucic  acid,  38,  39. 
Murexide,  49,  50. 

-test,  49,  50. 

Mustard-oil,  Methyl-,  13 
reaction,  12,  13.' 

N. 

Naphthalene,  6,  69. 
-monosulphonic  acids,  69. 
picrate,  69. 


80 


INDEX 


Naphthionate,  Sodium,  70. 
Naphthionic  acid,  70. 
Naphthol,  69. 
Naphthylamine,  a-,  70. 

P-,  70. 

Naphthylamines,  Test  for,  70. 
Nicotine,  73,  74. 
Nitrate,  Urea,  47,  48. 
Nitriles,  15. 

Hydrolysis  of,  15. 
Nitrite,  Ethyl,  13. 
Nitro-aniline,  m-,  64. 
o-,  64. 
p-,  64. 

-benzene,  50,  51,  53,  55,  72,  73. 

-celluloses,  41,  42. 

-compounds,  14,  15,  50. 

-methane,  14. 
Sodium,  14. 

-naphthalene,  «-,  69. 

-phenol,  o-,  62. 
P-,  62. 

-prusside-test,  4. 
Nitrogen,  Detection  of,  2. 
Nitrolic-acid  reaction,  14. 
Nitrosp-amine,  Diethyl-,  14. 

-amines,  14. 

-dimethylaniline.  55. 
hydrochloride,  55. 

-phenoxide.  Sodium,  55. 
Nitrous-acid  test,  13. 
Nitrous  acid,  Test  for,  64. 

O. 

Oil,  Almond,  25,  26. 

DIPPEL'S,  71. 

Linseed,  46. 

Turpentine,  67. 
Oleate,  Glyceryl,  25. 

Lead,  26. 

Sodium,  25. 
Olefines,  23,  24. 
Oleic  acid,  25. 
Osazones,  35,  36. 
Oxalate,  Ammonium,  29,  30. 

Calcium,  29. 

Copper,  29,  30. 
ammonium,  30. 

Diethyl,  31. 

Dimethyl,  30. 

Lead,  29. 


Oxalate,  Potassium,  28. 

ferric,  30. 
Sodium,  29. 
Urea,  47. 

Oxalates,  Complex,  30. 
Oxalic  acid,  7,    15,    16,    27,    28-31, 

47,  68. 
Oxamide,  31. 
Oxidation,  1,  3,  10,  17,  18,  23. 

P. 

Paper,  42. 

Paraffin-wax,  8. 

Parchment-paper,  41. 

Pentoses,  36. 

Petroleum,  6,  8. 

Phenol,  52,  53,  56,  62,  65,  66,  68. 

Ferric-chloride  test  for,  52. 

-phthalein,  66,  67. 
Phenoxide,  Sodium,  52. 
Phenyl-carbylamine,  54. 

-glucosazone,  35,  36. 

-hydrazine,   35,    36,   39,   57,   59. 

hydrochloride.  57. 
Phenylenediamine.  m-,  64. 

P-,  65, 
Phthalic  acid.  66. 

anhydride,  66 
Picramide,  64. 
Picrate.  Naphthalene,  69. 

Potassium,  62. 

Quinoline,  72. 

Picric  acid,  53,  62,  63,  69;  71,  72. 
Pinene  hydrochloride,  67. 
Polyoses,  40-42. 
Potassium  acetate,  38. 

benzote,  59,  60. 

calcium  Jerrocyanide,  44. 

cyanate,  45,  47. 

cyanide,  27,  44,  45,  46,  62. 

ethylsulphate,  12,  15. 

ferricyanide,  45. 

ferrocyanide,  15,  43;  44,  45,  57. 

formate,  27,  28. 

hydrogen  saccharate,  38. 
tartrate,  32,  33. 

isopurpurate,  62. 

mucate,  38. 

oxalate,  28. 

picrate,  62. 

propionate,  15. 


INDEX 


81 


Potassium  rosolate,  68. 

salt  of  alizarin,  70. 

silver  cyanide,  44. 

tartrate,  32. 

thiocyanate,  46. 

urate,  Di-,  49. 

xanthate,  47. 
Potato-starch,  41. 
Propionate,  Potassium,  15. 
Propionic  acid,  15. 
Propionitrile,  15. 
Proteins,  22, 42,  43,  66. 

Tests  for,  43. 

Prussian-blue  test,  2,  44,  45. 
Purpurate,  Ammonium,  49. 
Pyridine,  71. 

Test  for,  71. 
Pyrogallol,  63. 
Pyrrole-red,  71. 

Q. 

Qualitative  analysis  of  carbon  com- 
pounds, 1-4. 
Quinhydrone,  64. 
Quinine,  66,  74. 

hydrochloride,  66,  73. 

sulphate,  73,  74. 
Quinol,  63,  64. 
Quinoline,  72. 

dichromate,  73. 

hydrochloride,  72. 

picrate,  72. 

R. 

Racemate,  Calcium,  33. 

Racemicacid,  33. 

Reaction,  ADAMKIEWICZ'S,  43. 

Biuret-,  43,  48. 

Carbylamine-,  12,  54. 

FRIEDEL  and  CRAFTS'S,  51. 

GATTERMANN'S,  56. 

Indophenin-,  71,  72. 

Nitrolic-acid,  14. 

SCHIFF'S,  21. 

Xanthoprotein-,f  43 . 
Reagent,  MILLON'S,  43. 

SCHIFF'S,  21. 

SCHWEITZER'S,  41. 
Reagents,  Alkaloid-,  71,  73. 
Resin,  Aldehyde-,  21. 


Resorcinol,  38,  39,  63,  66. 
RocheUe  salt,  37. 
Rosolate,  Potassium,  68. 
Rosolic  acid,  68. 
Rye-bread,  36. 


S. 


Saccharate,  Calcium,  39. 

Potassium  hydrogen,  38. 
"  Saccharin,"  65. 
Salicylate,  Calcium,  52,  65. 
Salicylic  acid,  6,  65. 

Test  for,  65. 
Salting-out,  42. 
"  Salt  of  sorrel/'  30. 
"  Sand-sugar."     See  lactose. 
Saponification,  18-20,  25. 
Saturated  acids,  CnH2nO2,  15-20. 

dibasic  acids,  28-32. 

hydrocarbons,  7,  8. 
SCHIFF'S  reaction,  21. 

reagent,  21. 

SCHWEITZER'S  reagent,  41. 
Silver  acetate,  17. 

acetylene,  24. 

cyanide,  44. 

formate,  16. 

-mirror  test,  21,  32,  35,  59. 

potassium  cyanide,  44. 

thiocyanate,  46. 
SKRAUP'S  synthesis,  72. 
Smokeless  powder,  42. 
Soap,  19,  20. 
Sodium  acetate,  7,  17,  18,  56. 

benzenesulphonate,  50,  52,  57. 

ethoxide,  9,  14. 

formate,  29. 

methoxide,  61. 

methylnitrolate,  14. 

naphthionate,  70. 

nitromethane,  14. 

nitrosophenoxide,  55. 

oleate,  25. 

oxalate,  29. 

phenoxide,  52. 
Solvents,  Extraction  with,  6. 
Starch,  40,  41. 

Barium  alkoxide  of,  40. 

-paste,  40. 


82 


INDEX 


Starch.  Potato-,  41. 

Test  for,  40. 
Steam  distillation,  5,  6. 
Strychnine,  74. 

nitrate,  74. 

Test  for,  74. 
Succinate,  Barium,  31. 

Basic  ferric,  31. 
Succinic  acid,  31. 
Succinimide,  31. 
Sucrose,  1,  36,  39. 
Sugar.     See  sucrose. 

Cane-.     See  sucrose. 
Sugars,  35-42. 
Sulphanilic  acid,  64. 
Sulphur,  Detection  of,  3,  4. 

T. 

Tannin,  66, 71,  73. 

Test  for,  66. 
"  Tartar  emetic,"  33. 
Tartaric  acid,  32,  33. 
Tartrate,  Calcium,  33. 

Iron  ammonium,  32,  33. 

Potassium,  32. 

hydrogen,  32,  33. 
Test,  BEILSTEIN'S,  3. 

Cacodyl-,  17. 

Calcium-oxide,  3. 

CARIUS'S,  3. 

Caustic-alkali,  3,  4. 

CRISMER'S,  9,  10. 

Furfuraldehyde-,  36. 

lodoform-,  10,13,14,27. 

KJELDAHL'S,  2. 

La3vulose-,  38. 

LASSAIGNE'S,  2,  27. 

LIEBERMANN'S,  55. 

Murexide-,  49,  50. 

Mustard-oil,  12,  13. 

Nitroprusside-,  4. 

Nitrous-acid,  13. 

Prussian-blue,  2,  44,  45. 

Silver-mirror,  21,  32,  35,  59. 

WILL  and  VARRENTRAP'S,  2. 

for  acetone,  22. 
anthraquinone,  70. 
brucine,  74. 

hexoses,  Hydrochloric-acid,  36, 
37. 


Test  for  lignin,  42. 

naphthylamines,  70. 

nitrous    acid,    ra-Phenylenedi- 
amine,  64. 

phenol,  Ferric-chloride.  52. 

primary  amines,  12. 

pyridine,  77. 

salicylic  acid,  65. 

starch,  40. 

strychnine,  74. 

tannin,  66. 

the  double   bond,  VON  BAEY- 

ER'S,  24,  25,  50,  71. 
Tests    for    acetic    acid,     17,     18, 
??. 

aniline,  54. 

antipyrine,  72. 

carbon,  1,  2. 

ethyl  alcohol,  10,  27,  58. 

halogens,  2,  3. 

hydrogen,  1,  2. 

nitrogen,  2. 

proteins,  43. 

sulphur,  3,  4, 

water  in  alcohol,  9, 10. 
Tetramethylalloxantine,  50. 
Thiocyanate,  Ammonium,  3,  49. 
Ferric,  46,  49. 
Potassium,  46. 
Silver,  46. 
Thiophen,  72. 
Toluene,  51,  60. 
Transformation,  Elaidic,  25. 
Tribromo-aniline,  54. 
-phenol,  52. 
-resorcinol,  63. 
Trimethylamine,  14. 
Trinitrobenzene,  1:3:5-,  61. 
Triphenylmethane,  51. 
Trithiocarbonate,  Barium,  47. 
Turpentine,  Oil  of,  67. 

U. 

Unsaturated  acids,  Monobasic,  25, 
26. 

hydrocarbons,  23-25. 
Urate,  Ammonium,  49. 

Di-potassium,  49. 
Urea,  6,  47, 48,  55. 

nitrate,  47,  48. 

oxalate,  47. 


INDEX 


83 


Uric  acid,  49. 
Urine,  37,  47,  48. 
Estimation  of  urea  in,  48. 

V. 

VARRENTRAP'S  method,  WILL   and, 
2. 

W. 
Wax,  Paraffin-,  8. 


WILL  and  VARRENTRAP'S  method, 

2. 

Wine,  9. 

WOHLER'S  synthesis  of  urea,  47. 
Wood,  28. 
-charcoal,  4. 

X. 

Xanthate,  Cupric,  47. 

Cuprous,  47. 

Potassium,  47. 
Xanthoprote'in-reaction,  43. 


C  ! 

c  /- 1 


"- 


